Research ArticleExcellent Performance of Earth Dams under ResonanceMotion Using Isolator Damping Layer

Behrouz Gordan and Azlan Adnan

Engineering Seismology and Earthquake Engineering Research Group (e-SEER) Universiti Teknologi Malaysia81310 Skudai Johor Malaysia

Correspondence should be addressed to Azlan Adnan azlanadnanutmmy

Received 20 February 2014 Accepted 22 April 2014 Published 22 May 2014

Academic Editor Alicia Gonzalez-Buelga

Copyright copy 2014 B Gordan and A Adnan This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

The effect of blanket layer using isolator damping layer (IDL) between river sand foundation and short embankment to removedamage under severe earthquake was investigated in the present study In case of numerical analysis by ANSYS program dominantfrequency (DF)was computed by free vibration analysis Soilmechanic tests for thirteen samples to design IDL formulawere carriedout In terms of critical condition for earthquake effect such as resonance five physical small models were tested using vibrator tableunder the dominant frequency with scale parameter 1100 As a result dam was significantly damaged without blanket layer IDLIn order to reduce damage the best performance was observed using blanket layer (IDL) when this layer was expanded below thereservoir region The reinforced thickness layer size is one-fourth of dam height This method is a novel suggestion for earth damdesign in seismic zone

1 Introduction

The dynamic assessment dramatically has been started inearth dams after the observation of some damages duringthe earthquake In this domain huge damage such as bodycracks was recorded Totally this knowledge is correspon-dent to control dam behavior to avoid of failure processBesides earth dam construction is possible with respect tocompaction process Therefore the consolidation settlementcan be completely maximized at the end of construction Interms of earthquake effect on dam response the first phaseof total settlement is related to the final displacement in thestatic state Therefore total settlement is the superposition ofstatic and dynamic effect According to literature review inthis study a few cases of data monitoring was just recorded[1ndash3] Two cases such as the lack of data monitoring andtechnological development to provide computing programled to use of numeric method for dynamic analyzing Inthe other words the numerical analysis was commonlyutilized in several studies to predict dynamic behavior duringthe earthquake [4ndash9] In terms of analysis technique two

methods such as finite-element method (FEM) and finite-difference method (FDM) can be applied Dynamic analysisof earth dam was carried out by using two techniquessuch as two-dimensional and three-dimensional [10ndash13] Toselect plane strain (2D) and plane stress (3D) depends ondam configuration and valley shape in order to distributelateral strain [14] In terms of reinforcement methods somemethods have been used to reinforce dam in order to improvedynamic behavior along the earthquake [15ndash19] To verifyresults based on numeric analysis both tests such as shakingtable and centrifuge were successfully experienced [20ndash22]However to avoid dam failure by earthquake the effect offoundation soil was of a significant role to generate crackswith respect to increase of acceleration and displacementat the crest In the present study the main purpose is theimprovement of dam performance under severe motion likeresonance condition using blanket layer between foundationand homogenized earth dam In other words this paperpresents a novel method to remove damage by using newmaterial (IDL) In order to discuss level of damage in damfive physical models in regard to dominant frequency will

Hindawi Publishing CorporationShock and VibrationVolume 2014 Article ID 432760 15 pageshttpdxdoiorg1011552014432760

2 Shock and Vibration

be vibrated To improve dam performance the optimumthickness will be finally suggested

2 Laboratory Soil Tests

Two types of experimental tests were carried out in thisstudy Firstly soil mechanic tests were performed based onBritish Standard (BS) in order to design isolator dampinglayer (IDL) Secondly some small scale models with respectto finding the best location to reinforce dam were vibrated byusing vibrator table In terms of soil characters the BritishStandard (BS) for soil mechanic tests was used Based onsoil classification the local laterite soil MH was applied Thesummarizing of laterite properties is illustrated in Table 1 asused in this study

The passing percentage for different materials such aslaterite tire derived aggregate (TDA) and microsilica (MS)was shown in Figure 1 The determination of particle sizedistribution was carried out by using BS 1377-2 1990 Thisfigure shows that the amplitude of material size was locatedbetween 0075mm and 200mm Based on specific gravitytest this value forMSwasmore than TDAThese values wererespectively exposed at 242 and 215 Table 2 shows sampleswith respect to different mixtures to design IDL

According to soil laboratory test undrained shearstrength in the triaxial compression without measurement ofpore pressure (quick undrained) indicated that the strain insamples is increased by using more percentage of TDA it canbe observed in Figure 2 Also in this figure elasticitymodulusis reduced (see histograms in Figure 3) Significantly theyield point was dramatically reduced in this trend Withrespect to increasing flexibility by using maximum TDAfailure stress is possible with lower value Figure 3 showsthat the increase of TDA has effectively led to decrease ofelasticity modulus that was obtained with 9021 for sample5 In fact the elasticity modulus was significantly decreasedby using 10 TDA as mentioned previously Moreover themaximum and minimum values of modulus elasticity wererespectively obtained in sample 1 and sample 5 as can be seenin Figure 4 It is worth noting that the regular increase of themodulus was just found in sample 4 by increase ofmicrosilicawith 7 of TDA (see Figure 5 histogram without filling)In terms of flexibility distribution in samples the maximumand minimum value of the area below curve were located insample 8 and sample 5 as shown in Figure 6 In addition thegood convergence for sample 9 and sample 1 was obtainedIt should be noted that the quick undrained results werecomputed by average from three cases After all flexibilityfactor has the important role in order to absorb energy

According to consolidation test themaximum coefficientof volume compressibility was located in sample 6 with 0207while the minimum value was in sample 13 with 0081 (seeFigure 7(a)) It was revealed that the increase of TDA forsamples 1 to 5 caused increasing of rate regardless of sample 2In fact this coefficient was double value for sample 5with 10TDA In addition the minimum value was observed by 10TDA with 4 silica (see sample 12) Also in Figure 7(b) themaximum and minimum coefficient of consolidation were

Table 1 Characteristics of the laterite soil

Physical properties ValueSpecific gravity 240Liquid limit LL () 75Plastic limit PL () 41Plasticity index PI () 34BS classification MHMaximum dry density (g cmminus3) 133Optimum moisture content () 35Unconfined compressive strength (KPa) 30626Cohesion (KPa) 2518Angle of internal friction (degree) 3000Modulus elasticity (KPa) 1528372Coefficient of volume compressibility (mv m2MN) 01055Coefficient of consolidation (cv m2yr) 4416Permeability (cmseconds) 129119864 minus 5

Table 2 Sample definition

Sample number Component1 Laterite2 Laterite + 3 TDA3 Laterite + 5 TDA4 Laterite + 7 TDA5 Laterite + 10 TDA6 Laterite + 3 TDA + 2 silica7 Laterite + 3 TDA + 3 silica8 Laterite + 5 TDA + 2 silica9 Laterite + 5 TDA + 3 silica10 Laterite + 7 TDA + 3 silica11 Laterite + 7 TDA + 4 silica12 Laterite + 10 TDA + 4 silica13 Laterite + 10 TDA + 5 silica

respectively observed in sample 6 and sample 10 This factorwas progressively reduced by more percentage of TDA andsilicaTherefore the impact of silica to decrease consolidationcoefficient was greater than TDA

It should be noted that the determination of the one-dimensional consolidation properties based on BS 1377-51990 was carried out All samples were tested by using loadssuch as 25 50 999 19980 39970 and 7994 Kilo Pascal Inaddition in order to evaluate unloading effect to computecompression index the load of samples was declined withregard to 39970 19980 and 9990 Kilo Pascal In this testthe test duration for each sample was nine days Moreoverthe logarithmic-time method was used to identify void ratiodistribution with respect to applied pressure Consequentlyboth coefficients as discussed were computed by averagevalue based on different pressure with respect to loadingstages

In terms of permeability assessment sample 5 showsthe maximum permeability regarding use of 10TDA (see

Shock and Vibration 3

1006819

56833941

2729129533382

0102030405060708090

100

001 01 1 10 100

Fine

r (

)

Particle size (mm)

Laterite

(a)

Fine

r (

)

10097969388

6531

32661633

8172050102030405060708090

100

001 01 1 10 100Particle size (mm)

TDA

(b)Fi

ner (

)

10099328881

5966

37292204

1187340

102030405060708090

100

001 01 1 10 100

Particle size (mm)

MS

(c)

Figure 1 Distribution of gradation for different materials (a) Laterite (b) tire driven aggregate and (c) microsilica

00225 30626

006 16767

0065 10698

0045 2327400325 26357

000

5000

10000

15000

20000

25000

30000

35000

0 001 002 003 004 005 006 007 008

Sample 1Sample 4Sample 5

Sample 3Sample 2

Strain

Und

rain

ed sh

ear s

treng

th

Figure 2 Undrained shear strength in the triaxial compressionwithout measurement of pore pressure sample 1 to sample 5

0

2000

4000

6000

8000

10000

12000

14000

16000

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5

1528372

982937

733618

25826214959El

astic

ity m

odul

us (k

Pa)

Figure 3 Distribution of elasticity modulus in samples one to five

1528372

982937733618

25826214959

693668871086

971862850591

55811653648

436286265589

02000400060008000

1000012000140001600018000

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

Elas

ticity

mod

ulus

(kPa

)

Figure 4 Distribution of elasticity modulus in samples

Figure 8) However one of the major factors to design damis seepage controlling Therefore the permeability index wassignificantly improved by using more percentage of silicain this study In Figure 8 the minimum permeability wasobserved in sample 10 (167119864 minus 5 cms)

In terms of shear strength assessment using direct sheartest (small shear box apparatus) sample 10 indicated the bestperformance in order to increase both factors of cohesionand internal angle of friction Table 3 shows distribution ofcohesion and internal angle of friction in different samples

In order to estimate the damping ratio the nonlinearstress-strain characteristics of soils (Figure 9(a)) for anal-ysis purposes can be represented by bilinear relationships(Figure 9(b)) or multilinear relationships However the useof an equivalent linear viscoelastic analysis leads to similarresults Damping ratio depends on both areas as can be seen

4 Shock and Vibration

12000

10000

8000

6000

4000

2000

0

Sample 2 Sample 6 Sample 7

982937

693668

871086

(a)

12000

10000

8000

6000

4000

2000

0

Sample 3 Sample 8 Sample 9

733618

971862850591

(b)

Sample 4 Sample 10 Sample 11

7000

6000

5000

4000

3000

2000

1000

0

258262

55811

653648

(c)

Sample 5 Sample 12 Sample 13

5000

4000

3000

2000

1000

0

14959

436286

265589

(d)

Figure 5 Distribution of elasticity modulus (Kilo Pascal) for samples

377506

642489

327

593688 747

371 421514

333

61

012345678

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

Figure 6 Distribution of area under the curve of stress-strain basedon unconfined test

with blue and red colors in this figure [24] This ratio can begiven as follows

Damping ratio = 119863 = (1

4120587)

lowast (Loop area

area under stress strain curve)

(1)

However the area under stress strain curve and hysteresisloop area can be computed according to Figure 9 Figure 10shows damping ratio for sample 1 and sample 10 respectivelyIt can be seen that this ratio was 1795 in laterite soil Interms of soil improvement the damping coefficient increasedto 2263 for sample 10 (7 TDA with 3 silica)

After discussing all tests in soil mechanic that werecarried out sample 10 shows the excellent performance inorder to reinforce dam Therefore IDL material was defined

Table 3 Distribution of cohesion and angle of internal friction indifferent samples

Sample Cohesion (KPa) Friction (degree)1 2518 30002 1317 35013 2234 31074 1305 36335 301 29396 1474 3367 1682 33588 1815 33479 1557 363110 2638 321011 3494 285712 2711 286713 1486 3252

by using sample 10 In the physical small dam modeling thismaterial to reinforce dam in different location was used

For small scale modeling the river sand was used forfoundation Table 4 presents sand properties It is importantto note that river sand included uniform size particlesbecause uniformity coefficient was less than five In additioncoefficient of curvature was less than oneThe soil is said to bewell graded if this value lies between one and threeThereforethis type of sand was selected in order to critically conditionfoundation

Shock and Vibration 5

01055

0093301137

0117701566

0207

0111201163

00675

01533 01544

00625

0081

0

005

01

015

02

025

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

mv (average)

(m2M

N)

(a) Coefficient of volume compressibility

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

4416

3395

36076

31893463

8159

3118

28552487

11922659

1596

2311

0102030405060708090

cv (average)

(m2y

ear)

(b) Coefficient of consolidation

Figure 7 Distribution of coefficients in samples for consolidation test (a) Coefficient of volume compressibility and (b) coefficient ofconsolidation

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3Permeability (cms)

000E + 00

500E minus 05

100E minus 04

150E minus 04

200E minus 04

250E minus 04

300E minus 04

129E minus 05345E minus 05

613E minus 05

710E minus 05

242E minus 04

386E minus 05

450E minus 05

257E minus 05

322E minus 05

167E minus 05

206E minus 05

234E minus 04

213E minus 04

Figure 8 Distribution of permeability for different samples

Table 4 Sand properties

Physical properties ValueSpecific gravity 2547Cohesion (KPa) 000Angle of internal friction (Degree) 35Modulus elasticity (KPa) 32460Maximum dry density (grcm3) 172Minimum dry density (grcm3) 136Density for 119868

119889

= 75 (grcm3) 1613Permeability (cms) 01Maximum size (mm) 200Minimum size (mm) 0075Uniformity coefficient 119862

119906

4375Coefficient of curvature 119862

119888

097

3 Small Scale Model on Vibrator Table

Physical models with scale parameter equal to 1100 weretested In order to research methodology for this purposesome aspects included characteristic of vibrator table dis-placement transducer data logger sinusoidal motion scaleparameter for static or dynamic condition free vibrationanalysis and physical modeling will be presented In this

study five small scale dams were tested as will be explainedin the next section

31 Vibrator Table In this study vibrating table 24-9112(CN-166) with respect to sinus motion was used Figure 11shows the vibrating desk that was cushioned with steeland seminoiseless electromagnetic vibrator with 3600 vpmoperating frequency In addition it has a separate controllerto vary vibrator amplitude in case of frequency capacitylimit 100Hz Table capacity was equal to 750 lbs (340 kg)Double amplitude range was located at 0002 inch (005mm)to 0015 inch (038mm) Actuator was an electromagneticvibrator over 100 lbs (4530 kg)The table was square in shapeand 30 inch (762mm) The table thickness was 333mm ofsteel In case of weight it was net 555 lbs (252 kg) and shippingwas 605 lbs (274 kg) Figure 11 illustrates the vibrator table forthis study

32 Displacement Transducerand Data Logger Displacementtransducer CDP-D was utilized with respect to dual isolatedIO ports By using transducer one set of cables for input andoutput was connected to the analog measuring instrumentand another set to the digital measuring instrument Withtwo different types of measuring equipment connected tothis transducer simultaneous measurements can be madewithout interference Figure 12(a) shows the displacementtransducer and Figure 12(b) shows the dimensions for trans-ducer CDP-100 Tomeasure displacement at both edges of thecrest in small scale modeling two transducers were installedIn terms of data record data logger or data recorder is anelectronic device that records data over time or in relation tolocation with either a built in instrument or a sensor or viaexternal instruments and sensors

Figure 12(c) illustrates the data logger that was used inthis study Based on device ability results were printed duringthe vibration duration After that results were classified byusing Excel program It should be noted that both transducersas mentioned previously were connected to this data logger(UCAM-70A) in order to record vertical displacement duringthe vibration In addition the sub step of vibration periodwas

6 Shock and Vibration

Stress

Strain

(a)

Stress

Strain

(b)

Figure 9 Damping definition and hysteretic and equivalent bilinear stress-strain relationships for soil (a) stress-strain curves (b) bilinearidealization [23]

400

300

200

100

0

minus100

minus200

minus300

minus400

minus003 minus002 minus001 0 001 002 003

0020

00168

00225Stress (kPa)

Strain

Blue area = 377

Loop area = 850

Damping = 01795

Hysteresis loop-sample 1

(a)

250200150100500

minus50minus100minus150minus200minus250

minus006 minus004 minus002 0 002 004 006

00425

0034

00404

Stress (kPa)

Strain

Hysteresis loop-sample 10

Blue area = 421Loop area = 1197

Damping = 02263

(b)

Figure 10 Estimation of damping ratio (a) sample 1 and (b) sample 10

Figure 11 Vibrator table

equal to two seconds based on device ability with respect toprint

33 Sinusoidal Vibrate Loading There is a mathematicalrelationship between frequency displacement velocity andacceleration for sinusoidalmotion according to considerationof the peak value for them The relationship is such that ifany two of the four variables are known the other two can becalculated Table 5 shows all equations that were provided inthis context [25]

Table 5 Conversion for peak value in sinusoidal motion displace-ment (X) velocity (V) acceleration (A) and frequency (f )

Displacement X Velocity V Acceleration A

Displacement X 119883 = 119883 119883 =119881

2120587119891119883 =

119860

(2120587119891)2

Velocity V 119881 = 2120587119891119883 119881 = 119881 119881 =119860

2120587119891

Acceleration A 119860 = (2120587119891)2

119883 119860 = 2120587119891119881 119860 = 119860

119866 in these formulas is not gravity acceleration It is aconstant for calculation within different systems Respec-tively for metric imperial and Si 119866 is 980665ms23860885827 ins2 and 100ms2

Since themotion is sinusoidal the displacement velocityand acceleration are changing sinusoidal trend Howeverthey are not in the same phase The phase relationshipbetween displacement velocity and acceleration is that veloc-ity is 90∘ out of phase with acceleration and displacement is180∘ out of phase with acceleration

Shock and Vibration 7

(a)

CDP-D

12060110120601D

10

120601E

C A

120601BInputoutput 1Inputoutput 2

2 inputoutput cables

Dimensions

TypeCDP-50-D

A B C D E

165 335 65 5 10

(b)

(c)

Figure 12 Transducer and data logger (a) Displacement transducer CDP-100 (b) dimension of displacement transducer (CDP-100) and (c)data logger UCAM-70A

155

minus5minus15

20100

minus10minus20

25155

minus5minus15minus25

Displacement 13mm peak

Velocity 16336ms peak

Acceleration 2090gn peak

Figure 13 20Hz sinusoidal motion

In other words when displacement is at a maximumvelocity is at a minimum and acceleration is at a maximumIt should be noted that 1 119892

119899

= 980665ms2 = 32174 fts2 =3860886 ins2 Figure 13 shows the example of displacementdistribution with velocity and acceleration while the fre-quency of sinusoidal motion is twenty hertz

34 Scaling Laws In case of the scale parameter the scalefactor can be used according to

119909lowast

=119909119898

119909119901

(2)

The subscript 119898 represents ldquomodelrdquo and the subscript 119901represents ldquoprototyperdquo and 119909lowast represents the scale factor forthe quantity 119909 [26]

k

mx

Figure 14 Mass spring system

Figure 15 Free mesh

The reason for spinning a model on a centrifuge is toenable small scale models to feel the same effective stresses asa full scale prototype This goal can be stated mathematicallyas

1205901015840119909

=1205901015840

119898

1205901015840

119901

= 1 (3)

where the asterisk represents the scaling factor for thequantity 1205901015840

119898

is the effective stress in the model and 1205901015840119901

is theeffective stress in the prototype

8 Shock and Vibration

Nodal solutionStep = 1

UX (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0271E minus 04

Sub = 1X

Y

Z

MN

MX

minus0271E

minus04

minus0210E

minus04

minus0150E

minus04

minus0902Eminus05

minus0301Eminus05

0301Eminus05

0902Eminus05

0150E

minus04

0210E

minus04

0271E

minus04

SMN = minus0271E minus 04

Freq = 0229855

(a)

Nodal solutionStep = 1

Sub = 1

UY (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0126E minus 03

X

Y

Z

MN

MX

minus0971E

minus04

minus0125E

minus03

minus0692E

minus04

minus0413Eminus04

minus0134Eminus04

0145Eminus04

0423E

minus04

0702E

minus04

0981E

minus04

0126E

minus03

SMN = minus0125E minus 03

Freq = 0229855

(b)

X

Y

Z MN

MX

0

0287E

minus04

0575E

minus04

0862Eminus04

0115Eminus03

0144Eminus03

0172Eminus03

0201E

minus03

0230E

minus03

0259E

minus03

Nodal solutionStep = 1

UZ (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0259E minus 03

Sub = 1

Freq = 0229855

(c)

X

Y

Z

MX0

0320E

minus04

0639E

minus04

0959Eminus04

0128Eminus03

0160Eminus03

0192Eminus03

0224E

minus03

0256E

minus03

0288E

minus03

Nodal solutionStep = 1

Sub = 1

USUM (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0288E minus 03

MN

Freq = 0229855

(d)

Figure 16 Mode shape 1 (a) horizontal displacement (b) vertical displacement (c) lateral displacement and (d) total displacement

In soil mechanics the vertical effective stress 1205901015840 forexample is typically calculated by

1205901015840

= 120590119905

minus 119906 (4)

where 120590119905 and 119906 are total stress and pore pressure respectivelyFor a uniform layer with no pore pressure the total verticalstress at a depth119867may be calculated by

120590119905

= 120588119892119867 (5)

where 120588 represents the density of the layer and 119892 representsgravity In the conventional form of centrifugemodeling [26]it is typical that the same materials are used in the model andprototype therefore the densities are the same in model andprototype that is

120588lowast

= 1 (6)

Furthermore in conventional centrifugemodeling all lengthsare scaled by the same factor 119871lowast To produce the same stressin the model as in the prototype we thus require

120588lowast

119892lowast

119867lowast

= 1119892lowast

119871lowast

= 1 (7)

It may be rewritten as

119892lowast

=1

119871lowast

(8)

The above scaling law states that if lengths in the model arereduced by some factor 119899 then gravitational accelerationsmust be increased by the same factor 119899 in order to preserveequal stresses in model and prototype

Shock and Vibration 9

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(a)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(b)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(c)

1650

950

500 5200 500

1000

1000785 Water

Sand

Laterite reinforced

(d)

1650

950

1000

1000785

Laterite

Water

Sand

500 5200 500

(e)

Figure 17 Model introducing ((a) (b) (c) (d) and (e)) for small dam (cm) (119878 = 1100)

For dynamic problems where gravity and accelerationsare important all accelerations must scale as gravity is scaledthat is

119886lowast

= 119892lowast

=1

119871lowast

(9)

Since acceleration has units of 1198711198792 it is required that

119886lowast

=119871lowast

1198792

(10)

Hence it is required that

1

119871lowast

=119871lowast

1198792

or 119879lowast

= 119871lowast

(11)

Frequency has units of inverse of time and velocity has unitsof length per time so for dynamic problems we also obtain

119891lowast

=1

119871lowast

Vlowast =119871lowast

119879lowast

= 1 (12)

For model tests involving dynamics the conflict in time scalefactors may be resolved by scaling the permeability of the soil[26]

35 Free Vibration Analysis In dynamic assessment freevibration analysis is the base of study In fact the distributionof frequency in the different vibrationmode can be computedby the application of modal analysis based on finite-elementmethod (FEM) It is worth mentioning that this analysis isperfectly related to the mass and spring In case of the mass-spring-damper system the first assumption is negligibleabout damping effect Therefore there is not any externalforce on mass in this state The force applied to the massby the spring is proportional to the amount of the springthat is stretched ldquo119909rdquo (it can be assumed that spring isalready compressed due to the weight of the mass) Theproportionality constant (119896) is spring stiffness (see Figure 14)The unit measurement is force divided by distance (kgm)

10 Shock and Vibration

(a) (b)

(c) (d)

Figure 18 Small scale dam (a) Dam perspective with two LVDT (b) soil compaction with roller (c) dam section with index network and(d) dam with tank before vibration

The negative sign indicates that force is always opposingthe motion of the mass attached to it according to thefollowing equation

119865119904

= minus119896119909 (13)

The force generated by the mass is proportional to theacceleration of the mass as given by Newtonrsquos second law ofmotion

sum119865 = 119898119886 = 119898 = 1198981198892

119909

1198891199052

(14)

The sumof the forces on themass then generates this ordinarydifferential equation

119898 + 119896119909 = 0 (15)

Assuming that the initial vibration can be started by stretch-ing and releasing the spring with distance (119860) the solution tothe above equation that describes the motion of mass can beseen in the following equation

119909 (119905) = 119860 cos (2120587119891119899

119905) (16)

This solution shows that it will oscillate with simple harmonicmotion that has amplitude of (119860) and a frequency (119891

119899

) Thenumber (119891

119899

) is called the undamped natural frequency Forthe simple mass-spring system frequency is given by

119891119899

=1

2120587

radic119896

119898 (17)

However the relation between frequency and vibrationperiod is always reverse Consider

119879 =1

119891 (18)

In terms of the measurement unit the vibration periodand frequency were according to seconds and hertz It isworth noting that the dominant frequency is the minimumfrequency to produce maximum vibration period

4 Numerical Analysis

In terms of numerical analysismodal analysis was carried outby using ANSYS program in this study to compute dominantfrequency for small scale model regarding 3D analysis Thisprogram is one of the famous software programs with respectto finite-elementmethod (FEM) In particular this software isone of the universal programs with high level of the ability fordifferent analyses A strong ability to compute free vibrationanalysis is possible with modal analysis [27]

41 Elements and Meshing Process To select element basedon Help menu solid 8 nodes 183 (3D) were used for thispurpose Figure 15 shows the mapped mesh for numericalmodeling In this figure 23956 elements and 35457 nodes inmodels were used for free vibration analysis According tothis condition free vibration analysis to access frequency indifferent vibration modes was carried out as results can bediscussed in the next section

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

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Shock and Vibration

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International Journal of

2 Shock and Vibration

be vibrated To improve dam performance the optimumthickness will be finally suggested

2 Laboratory Soil Tests

Two types of experimental tests were carried out in thisstudy Firstly soil mechanic tests were performed based onBritish Standard (BS) in order to design isolator dampinglayer (IDL) Secondly some small scale models with respectto finding the best location to reinforce dam were vibrated byusing vibrator table In terms of soil characters the BritishStandard (BS) for soil mechanic tests was used Based onsoil classification the local laterite soil MH was applied Thesummarizing of laterite properties is illustrated in Table 1 asused in this study

The passing percentage for different materials such aslaterite tire derived aggregate (TDA) and microsilica (MS)was shown in Figure 1 The determination of particle sizedistribution was carried out by using BS 1377-2 1990 Thisfigure shows that the amplitude of material size was locatedbetween 0075mm and 200mm Based on specific gravitytest this value forMSwasmore than TDAThese values wererespectively exposed at 242 and 215 Table 2 shows sampleswith respect to different mixtures to design IDL

According to soil laboratory test undrained shearstrength in the triaxial compression without measurement ofpore pressure (quick undrained) indicated that the strain insamples is increased by using more percentage of TDA it canbe observed in Figure 2 Also in this figure elasticitymodulusis reduced (see histograms in Figure 3) Significantly theyield point was dramatically reduced in this trend Withrespect to increasing flexibility by using maximum TDAfailure stress is possible with lower value Figure 3 showsthat the increase of TDA has effectively led to decrease ofelasticity modulus that was obtained with 9021 for sample5 In fact the elasticity modulus was significantly decreasedby using 10 TDA as mentioned previously Moreover themaximum and minimum values of modulus elasticity wererespectively obtained in sample 1 and sample 5 as can be seenin Figure 4 It is worth noting that the regular increase of themodulus was just found in sample 4 by increase ofmicrosilicawith 7 of TDA (see Figure 5 histogram without filling)In terms of flexibility distribution in samples the maximumand minimum value of the area below curve were located insample 8 and sample 5 as shown in Figure 6 In addition thegood convergence for sample 9 and sample 1 was obtainedIt should be noted that the quick undrained results werecomputed by average from three cases After all flexibilityfactor has the important role in order to absorb energy

According to consolidation test themaximum coefficientof volume compressibility was located in sample 6 with 0207while the minimum value was in sample 13 with 0081 (seeFigure 7(a)) It was revealed that the increase of TDA forsamples 1 to 5 caused increasing of rate regardless of sample 2In fact this coefficient was double value for sample 5with 10TDA In addition the minimum value was observed by 10TDA with 4 silica (see sample 12) Also in Figure 7(b) themaximum and minimum coefficient of consolidation were

Table 1 Characteristics of the laterite soil

Physical properties ValueSpecific gravity 240Liquid limit LL () 75Plastic limit PL () 41Plasticity index PI () 34BS classification MHMaximum dry density (g cmminus3) 133Optimum moisture content () 35Unconfined compressive strength (KPa) 30626Cohesion (KPa) 2518Angle of internal friction (degree) 3000Modulus elasticity (KPa) 1528372Coefficient of volume compressibility (mv m2MN) 01055Coefficient of consolidation (cv m2yr) 4416Permeability (cmseconds) 129119864 minus 5

Table 2 Sample definition

Sample number Component1 Laterite2 Laterite + 3 TDA3 Laterite + 5 TDA4 Laterite + 7 TDA5 Laterite + 10 TDA6 Laterite + 3 TDA + 2 silica7 Laterite + 3 TDA + 3 silica8 Laterite + 5 TDA + 2 silica9 Laterite + 5 TDA + 3 silica10 Laterite + 7 TDA + 3 silica11 Laterite + 7 TDA + 4 silica12 Laterite + 10 TDA + 4 silica13 Laterite + 10 TDA + 5 silica

respectively observed in sample 6 and sample 10 This factorwas progressively reduced by more percentage of TDA andsilicaTherefore the impact of silica to decrease consolidationcoefficient was greater than TDA

It should be noted that the determination of the one-dimensional consolidation properties based on BS 1377-51990 was carried out All samples were tested by using loadssuch as 25 50 999 19980 39970 and 7994 Kilo Pascal Inaddition in order to evaluate unloading effect to computecompression index the load of samples was declined withregard to 39970 19980 and 9990 Kilo Pascal In this testthe test duration for each sample was nine days Moreoverthe logarithmic-time method was used to identify void ratiodistribution with respect to applied pressure Consequentlyboth coefficients as discussed were computed by averagevalue based on different pressure with respect to loadingstages

In terms of permeability assessment sample 5 showsthe maximum permeability regarding use of 10TDA (see

Shock and Vibration 3

1006819

56833941

2729129533382

0102030405060708090

100

001 01 1 10 100

Fine

r (

)

Particle size (mm)

Laterite

(a)

Fine

r (

)

10097969388

6531

32661633

8172050102030405060708090

100

001 01 1 10 100Particle size (mm)

TDA

(b)Fi

ner (

)

10099328881

5966

37292204

1187340

102030405060708090

100

001 01 1 10 100

Particle size (mm)

MS

(c)

Figure 1 Distribution of gradation for different materials (a) Laterite (b) tire driven aggregate and (c) microsilica

00225 30626

006 16767

0065 10698

0045 2327400325 26357

000

5000

10000

15000

20000

25000

30000

35000

0 001 002 003 004 005 006 007 008

Sample 1Sample 4Sample 5

Sample 3Sample 2

Strain

Und

rain

ed sh

ear s

treng

th

Figure 2 Undrained shear strength in the triaxial compressionwithout measurement of pore pressure sample 1 to sample 5

0

2000

4000

6000

8000

10000

12000

14000

16000

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5

1528372

982937

733618

25826214959El

astic

ity m

odul

us (k

Pa)

Figure 3 Distribution of elasticity modulus in samples one to five

1528372

982937733618

25826214959

693668871086

971862850591

55811653648

436286265589

02000400060008000

1000012000140001600018000

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

Elas

ticity

mod

ulus

(kPa

)

Figure 4 Distribution of elasticity modulus in samples

Figure 8) However one of the major factors to design damis seepage controlling Therefore the permeability index wassignificantly improved by using more percentage of silicain this study In Figure 8 the minimum permeability wasobserved in sample 10 (167119864 minus 5 cms)

In terms of shear strength assessment using direct sheartest (small shear box apparatus) sample 10 indicated the bestperformance in order to increase both factors of cohesionand internal angle of friction Table 3 shows distribution ofcohesion and internal angle of friction in different samples

In order to estimate the damping ratio the nonlinearstress-strain characteristics of soils (Figure 9(a)) for anal-ysis purposes can be represented by bilinear relationships(Figure 9(b)) or multilinear relationships However the useof an equivalent linear viscoelastic analysis leads to similarresults Damping ratio depends on both areas as can be seen

4 Shock and Vibration

12000

10000

8000

6000

4000

2000

0

Sample 2 Sample 6 Sample 7

982937

693668

871086

(a)

12000

10000

8000

6000

4000

2000

0

Sample 3 Sample 8 Sample 9

733618

971862850591

(b)

Sample 4 Sample 10 Sample 11

7000

6000

5000

4000

3000

2000

1000

0

258262

55811

653648

(c)

Sample 5 Sample 12 Sample 13

5000

4000

3000

2000

1000

0

14959

436286

265589

(d)

Figure 5 Distribution of elasticity modulus (Kilo Pascal) for samples

377506

642489

327

593688 747

371 421514

333

61

012345678

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

Figure 6 Distribution of area under the curve of stress-strain basedon unconfined test

with blue and red colors in this figure [24] This ratio can begiven as follows

Damping ratio = 119863 = (1

4120587)

lowast (Loop area

area under stress strain curve)

(1)

However the area under stress strain curve and hysteresisloop area can be computed according to Figure 9 Figure 10shows damping ratio for sample 1 and sample 10 respectivelyIt can be seen that this ratio was 1795 in laterite soil Interms of soil improvement the damping coefficient increasedto 2263 for sample 10 (7 TDA with 3 silica)

After discussing all tests in soil mechanic that werecarried out sample 10 shows the excellent performance inorder to reinforce dam Therefore IDL material was defined

Table 3 Distribution of cohesion and angle of internal friction indifferent samples

Sample Cohesion (KPa) Friction (degree)1 2518 30002 1317 35013 2234 31074 1305 36335 301 29396 1474 3367 1682 33588 1815 33479 1557 363110 2638 321011 3494 285712 2711 286713 1486 3252

by using sample 10 In the physical small dam modeling thismaterial to reinforce dam in different location was used

For small scale modeling the river sand was used forfoundation Table 4 presents sand properties It is importantto note that river sand included uniform size particlesbecause uniformity coefficient was less than five In additioncoefficient of curvature was less than oneThe soil is said to bewell graded if this value lies between one and threeThereforethis type of sand was selected in order to critically conditionfoundation

Shock and Vibration 5

01055

0093301137

0117701566

0207

0111201163

00675

01533 01544

00625

0081

0

005

01

015

02

025

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

mv (average)

(m2M

N)

(a) Coefficient of volume compressibility

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

4416

3395

36076

31893463

8159

3118

28552487

11922659

1596

2311

0102030405060708090

cv (average)

(m2y

ear)

(b) Coefficient of consolidation

Figure 7 Distribution of coefficients in samples for consolidation test (a) Coefficient of volume compressibility and (b) coefficient ofconsolidation

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3Permeability (cms)

000E + 00

500E minus 05

100E minus 04

150E minus 04

200E minus 04

250E minus 04

300E minus 04

129E minus 05345E minus 05

613E minus 05

710E minus 05

242E minus 04

386E minus 05

450E minus 05

257E minus 05

322E minus 05

167E minus 05

206E minus 05

234E minus 04

213E minus 04

Figure 8 Distribution of permeability for different samples

Table 4 Sand properties

Physical properties ValueSpecific gravity 2547Cohesion (KPa) 000Angle of internal friction (Degree) 35Modulus elasticity (KPa) 32460Maximum dry density (grcm3) 172Minimum dry density (grcm3) 136Density for 119868

119889

= 75 (grcm3) 1613Permeability (cms) 01Maximum size (mm) 200Minimum size (mm) 0075Uniformity coefficient 119862

119906

4375Coefficient of curvature 119862

119888

097

3 Small Scale Model on Vibrator Table

Physical models with scale parameter equal to 1100 weretested In order to research methodology for this purposesome aspects included characteristic of vibrator table dis-placement transducer data logger sinusoidal motion scaleparameter for static or dynamic condition free vibrationanalysis and physical modeling will be presented In this

study five small scale dams were tested as will be explainedin the next section

31 Vibrator Table In this study vibrating table 24-9112(CN-166) with respect to sinus motion was used Figure 11shows the vibrating desk that was cushioned with steeland seminoiseless electromagnetic vibrator with 3600 vpmoperating frequency In addition it has a separate controllerto vary vibrator amplitude in case of frequency capacitylimit 100Hz Table capacity was equal to 750 lbs (340 kg)Double amplitude range was located at 0002 inch (005mm)to 0015 inch (038mm) Actuator was an electromagneticvibrator over 100 lbs (4530 kg)The table was square in shapeand 30 inch (762mm) The table thickness was 333mm ofsteel In case of weight it was net 555 lbs (252 kg) and shippingwas 605 lbs (274 kg) Figure 11 illustrates the vibrator table forthis study

32 Displacement Transducerand Data Logger Displacementtransducer CDP-D was utilized with respect to dual isolatedIO ports By using transducer one set of cables for input andoutput was connected to the analog measuring instrumentand another set to the digital measuring instrument Withtwo different types of measuring equipment connected tothis transducer simultaneous measurements can be madewithout interference Figure 12(a) shows the displacementtransducer and Figure 12(b) shows the dimensions for trans-ducer CDP-100 Tomeasure displacement at both edges of thecrest in small scale modeling two transducers were installedIn terms of data record data logger or data recorder is anelectronic device that records data over time or in relation tolocation with either a built in instrument or a sensor or viaexternal instruments and sensors

Figure 12(c) illustrates the data logger that was used inthis study Based on device ability results were printed duringthe vibration duration After that results were classified byusing Excel program It should be noted that both transducersas mentioned previously were connected to this data logger(UCAM-70A) in order to record vertical displacement duringthe vibration In addition the sub step of vibration periodwas

6 Shock and Vibration

Stress

Strain

(a)

Stress

Strain

(b)

Figure 9 Damping definition and hysteretic and equivalent bilinear stress-strain relationships for soil (a) stress-strain curves (b) bilinearidealization [23]

400

300

200

100

0

minus100

minus200

minus300

minus400

minus003 minus002 minus001 0 001 002 003

0020

00168

00225Stress (kPa)

Strain

Blue area = 377

Loop area = 850

Damping = 01795

Hysteresis loop-sample 1

(a)

250200150100500

minus50minus100minus150minus200minus250

minus006 minus004 minus002 0 002 004 006

00425

0034

00404

Stress (kPa)

Strain

Hysteresis loop-sample 10

Blue area = 421Loop area = 1197

Damping = 02263

(b)

Figure 10 Estimation of damping ratio (a) sample 1 and (b) sample 10

Figure 11 Vibrator table

equal to two seconds based on device ability with respect toprint

33 Sinusoidal Vibrate Loading There is a mathematicalrelationship between frequency displacement velocity andacceleration for sinusoidalmotion according to considerationof the peak value for them The relationship is such that ifany two of the four variables are known the other two can becalculated Table 5 shows all equations that were provided inthis context [25]

Table 5 Conversion for peak value in sinusoidal motion displace-ment (X) velocity (V) acceleration (A) and frequency (f )

Displacement X Velocity V Acceleration A

Displacement X 119883 = 119883 119883 =119881

2120587119891119883 =

119860

(2120587119891)2

Velocity V 119881 = 2120587119891119883 119881 = 119881 119881 =119860

2120587119891

Acceleration A 119860 = (2120587119891)2

119883 119860 = 2120587119891119881 119860 = 119860

119866 in these formulas is not gravity acceleration It is aconstant for calculation within different systems Respec-tively for metric imperial and Si 119866 is 980665ms23860885827 ins2 and 100ms2

Since themotion is sinusoidal the displacement velocityand acceleration are changing sinusoidal trend Howeverthey are not in the same phase The phase relationshipbetween displacement velocity and acceleration is that veloc-ity is 90∘ out of phase with acceleration and displacement is180∘ out of phase with acceleration

Shock and Vibration 7

(a)

CDP-D

12060110120601D

10

120601E

C A

120601BInputoutput 1Inputoutput 2

2 inputoutput cables

Dimensions

TypeCDP-50-D

A B C D E

165 335 65 5 10

(b)

(c)

Figure 12 Transducer and data logger (a) Displacement transducer CDP-100 (b) dimension of displacement transducer (CDP-100) and (c)data logger UCAM-70A

155

minus5minus15

20100

minus10minus20

25155

minus5minus15minus25

Displacement 13mm peak

Velocity 16336ms peak

Acceleration 2090gn peak

Figure 13 20Hz sinusoidal motion

In other words when displacement is at a maximumvelocity is at a minimum and acceleration is at a maximumIt should be noted that 1 119892

119899

= 980665ms2 = 32174 fts2 =3860886 ins2 Figure 13 shows the example of displacementdistribution with velocity and acceleration while the fre-quency of sinusoidal motion is twenty hertz

34 Scaling Laws In case of the scale parameter the scalefactor can be used according to

119909lowast

=119909119898

119909119901

(2)

The subscript 119898 represents ldquomodelrdquo and the subscript 119901represents ldquoprototyperdquo and 119909lowast represents the scale factor forthe quantity 119909 [26]

k

mx

Figure 14 Mass spring system

Figure 15 Free mesh

The reason for spinning a model on a centrifuge is toenable small scale models to feel the same effective stresses asa full scale prototype This goal can be stated mathematicallyas

1205901015840119909

=1205901015840

119898

1205901015840

119901

= 1 (3)

where the asterisk represents the scaling factor for thequantity 1205901015840

119898

is the effective stress in the model and 1205901015840119901

is theeffective stress in the prototype

8 Shock and Vibration

Nodal solutionStep = 1

UX (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0271E minus 04

Sub = 1X

Y

Z

MN

MX

minus0271E

minus04

minus0210E

minus04

minus0150E

minus04

minus0902Eminus05

minus0301Eminus05

0301Eminus05

0902Eminus05

0150E

minus04

0210E

minus04

0271E

minus04

SMN = minus0271E minus 04

Freq = 0229855

(a)

Nodal solutionStep = 1

Sub = 1

UY (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0126E minus 03

X

Y

Z

MN

MX

minus0971E

minus04

minus0125E

minus03

minus0692E

minus04

minus0413Eminus04

minus0134Eminus04

0145Eminus04

0423E

minus04

0702E

minus04

0981E

minus04

0126E

minus03

SMN = minus0125E minus 03

Freq = 0229855

(b)

X

Y

Z MN

MX

0

0287E

minus04

0575E

minus04

0862Eminus04

0115Eminus03

0144Eminus03

0172Eminus03

0201E

minus03

0230E

minus03

0259E

minus03

Nodal solutionStep = 1

UZ (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0259E minus 03

Sub = 1

Freq = 0229855

(c)

X

Y

Z

MX0

0320E

minus04

0639E

minus04

0959Eminus04

0128Eminus03

0160Eminus03

0192Eminus03

0224E

minus03

0256E

minus03

0288E

minus03

Nodal solutionStep = 1

Sub = 1

USUM (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0288E minus 03

MN

Freq = 0229855

(d)

Figure 16 Mode shape 1 (a) horizontal displacement (b) vertical displacement (c) lateral displacement and (d) total displacement

In soil mechanics the vertical effective stress 1205901015840 forexample is typically calculated by

1205901015840

= 120590119905

minus 119906 (4)

where 120590119905 and 119906 are total stress and pore pressure respectivelyFor a uniform layer with no pore pressure the total verticalstress at a depth119867may be calculated by

120590119905

= 120588119892119867 (5)

where 120588 represents the density of the layer and 119892 representsgravity In the conventional form of centrifugemodeling [26]it is typical that the same materials are used in the model andprototype therefore the densities are the same in model andprototype that is

120588lowast

= 1 (6)

Furthermore in conventional centrifugemodeling all lengthsare scaled by the same factor 119871lowast To produce the same stressin the model as in the prototype we thus require

120588lowast

119892lowast

119867lowast

= 1119892lowast

119871lowast

= 1 (7)

It may be rewritten as

119892lowast

=1

119871lowast

(8)

The above scaling law states that if lengths in the model arereduced by some factor 119899 then gravitational accelerationsmust be increased by the same factor 119899 in order to preserveequal stresses in model and prototype

Shock and Vibration 9

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(a)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(b)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(c)

1650

950

500 5200 500

1000

1000785 Water

Sand

Laterite reinforced

(d)

1650

950

1000

1000785

Laterite

Water

Sand

500 5200 500

(e)

Figure 17 Model introducing ((a) (b) (c) (d) and (e)) for small dam (cm) (119878 = 1100)

For dynamic problems where gravity and accelerationsare important all accelerations must scale as gravity is scaledthat is

119886lowast

= 119892lowast

=1

119871lowast

(9)

Since acceleration has units of 1198711198792 it is required that

119886lowast

=119871lowast

1198792

(10)

Hence it is required that

1

119871lowast

=119871lowast

1198792

or 119879lowast

= 119871lowast

(11)

Frequency has units of inverse of time and velocity has unitsof length per time so for dynamic problems we also obtain

119891lowast

=1

119871lowast

Vlowast =119871lowast

119879lowast

= 1 (12)

For model tests involving dynamics the conflict in time scalefactors may be resolved by scaling the permeability of the soil[26]

35 Free Vibration Analysis In dynamic assessment freevibration analysis is the base of study In fact the distributionof frequency in the different vibrationmode can be computedby the application of modal analysis based on finite-elementmethod (FEM) It is worth mentioning that this analysis isperfectly related to the mass and spring In case of the mass-spring-damper system the first assumption is negligibleabout damping effect Therefore there is not any externalforce on mass in this state The force applied to the massby the spring is proportional to the amount of the springthat is stretched ldquo119909rdquo (it can be assumed that spring isalready compressed due to the weight of the mass) Theproportionality constant (119896) is spring stiffness (see Figure 14)The unit measurement is force divided by distance (kgm)

10 Shock and Vibration

(a) (b)

(c) (d)

Figure 18 Small scale dam (a) Dam perspective with two LVDT (b) soil compaction with roller (c) dam section with index network and(d) dam with tank before vibration

The negative sign indicates that force is always opposingthe motion of the mass attached to it according to thefollowing equation

119865119904

= minus119896119909 (13)

The force generated by the mass is proportional to theacceleration of the mass as given by Newtonrsquos second law ofmotion

sum119865 = 119898119886 = 119898 = 1198981198892

119909

1198891199052

(14)

The sumof the forces on themass then generates this ordinarydifferential equation

119898 + 119896119909 = 0 (15)

Assuming that the initial vibration can be started by stretch-ing and releasing the spring with distance (119860) the solution tothe above equation that describes the motion of mass can beseen in the following equation

119909 (119905) = 119860 cos (2120587119891119899

119905) (16)

This solution shows that it will oscillate with simple harmonicmotion that has amplitude of (119860) and a frequency (119891

119899

) Thenumber (119891

119899

) is called the undamped natural frequency Forthe simple mass-spring system frequency is given by

119891119899

=1

2120587

radic119896

119898 (17)

However the relation between frequency and vibrationperiod is always reverse Consider

119879 =1

119891 (18)

In terms of the measurement unit the vibration periodand frequency were according to seconds and hertz It isworth noting that the dominant frequency is the minimumfrequency to produce maximum vibration period

4 Numerical Analysis

In terms of numerical analysismodal analysis was carried outby using ANSYS program in this study to compute dominantfrequency for small scale model regarding 3D analysis Thisprogram is one of the famous software programs with respectto finite-elementmethod (FEM) In particular this software isone of the universal programs with high level of the ability fordifferent analyses A strong ability to compute free vibrationanalysis is possible with modal analysis [27]

41 Elements and Meshing Process To select element basedon Help menu solid 8 nodes 183 (3D) were used for thispurpose Figure 15 shows the mapped mesh for numericalmodeling In this figure 23956 elements and 35457 nodes inmodels were used for free vibration analysis According tothis condition free vibration analysis to access frequency indifferent vibration modes was carried out as results can bediscussed in the next section

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

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Shock and Vibration

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International Journal of

Shock and Vibration 3

1006819

56833941

2729129533382

0102030405060708090

100

001 01 1 10 100

Fine

r (

)

Particle size (mm)

Laterite

(a)

Fine

r (

)

10097969388

6531

32661633

8172050102030405060708090

100

001 01 1 10 100Particle size (mm)

TDA

(b)Fi

ner (

)

10099328881

5966

37292204

1187340

102030405060708090

100

001 01 1 10 100

Particle size (mm)

MS

(c)

Figure 1 Distribution of gradation for different materials (a) Laterite (b) tire driven aggregate and (c) microsilica

00225 30626

006 16767

0065 10698

0045 2327400325 26357

000

5000

10000

15000

20000

25000

30000

35000

0 001 002 003 004 005 006 007 008

Sample 1Sample 4Sample 5

Sample 3Sample 2

Strain

Und

rain

ed sh

ear s

treng

th

Figure 2 Undrained shear strength in the triaxial compressionwithout measurement of pore pressure sample 1 to sample 5

0

2000

4000

6000

8000

10000

12000

14000

16000

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5

1528372

982937

733618

25826214959El

astic

ity m

odul

us (k

Pa)

Figure 3 Distribution of elasticity modulus in samples one to five

1528372

982937733618

25826214959

693668871086

971862850591

55811653648

436286265589

02000400060008000

1000012000140001600018000

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

Elas

ticity

mod

ulus

(kPa

)

Figure 4 Distribution of elasticity modulus in samples

Figure 8) However one of the major factors to design damis seepage controlling Therefore the permeability index wassignificantly improved by using more percentage of silicain this study In Figure 8 the minimum permeability wasobserved in sample 10 (167119864 minus 5 cms)

In terms of shear strength assessment using direct sheartest (small shear box apparatus) sample 10 indicated the bestperformance in order to increase both factors of cohesionand internal angle of friction Table 3 shows distribution ofcohesion and internal angle of friction in different samples

In order to estimate the damping ratio the nonlinearstress-strain characteristics of soils (Figure 9(a)) for anal-ysis purposes can be represented by bilinear relationships(Figure 9(b)) or multilinear relationships However the useof an equivalent linear viscoelastic analysis leads to similarresults Damping ratio depends on both areas as can be seen

4 Shock and Vibration

12000

10000

8000

6000

4000

2000

0

Sample 2 Sample 6 Sample 7

982937

693668

871086

(a)

12000

10000

8000

6000

4000

2000

0

Sample 3 Sample 8 Sample 9

733618

971862850591

(b)

Sample 4 Sample 10 Sample 11

7000

6000

5000

4000

3000

2000

1000

0

258262

55811

653648

(c)

Sample 5 Sample 12 Sample 13

5000

4000

3000

2000

1000

0

14959

436286

265589

(d)

Figure 5 Distribution of elasticity modulus (Kilo Pascal) for samples

377506

642489

327

593688 747

371 421514

333

61

012345678

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

Figure 6 Distribution of area under the curve of stress-strain basedon unconfined test

with blue and red colors in this figure [24] This ratio can begiven as follows

Damping ratio = 119863 = (1

4120587)

lowast (Loop area

area under stress strain curve)

(1)

However the area under stress strain curve and hysteresisloop area can be computed according to Figure 9 Figure 10shows damping ratio for sample 1 and sample 10 respectivelyIt can be seen that this ratio was 1795 in laterite soil Interms of soil improvement the damping coefficient increasedto 2263 for sample 10 (7 TDA with 3 silica)

After discussing all tests in soil mechanic that werecarried out sample 10 shows the excellent performance inorder to reinforce dam Therefore IDL material was defined

Table 3 Distribution of cohesion and angle of internal friction indifferent samples

Sample Cohesion (KPa) Friction (degree)1 2518 30002 1317 35013 2234 31074 1305 36335 301 29396 1474 3367 1682 33588 1815 33479 1557 363110 2638 321011 3494 285712 2711 286713 1486 3252

by using sample 10 In the physical small dam modeling thismaterial to reinforce dam in different location was used

For small scale modeling the river sand was used forfoundation Table 4 presents sand properties It is importantto note that river sand included uniform size particlesbecause uniformity coefficient was less than five In additioncoefficient of curvature was less than oneThe soil is said to bewell graded if this value lies between one and threeThereforethis type of sand was selected in order to critically conditionfoundation

Shock and Vibration 5

01055

0093301137

0117701566

0207

0111201163

00675

01533 01544

00625

0081

0

005

01

015

02

025

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

mv (average)

(m2M

N)

(a) Coefficient of volume compressibility

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

4416

3395

36076

31893463

8159

3118

28552487

11922659

1596

2311

0102030405060708090

cv (average)

(m2y

ear)

(b) Coefficient of consolidation

Figure 7 Distribution of coefficients in samples for consolidation test (a) Coefficient of volume compressibility and (b) coefficient ofconsolidation

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3Permeability (cms)

000E + 00

500E minus 05

100E minus 04

150E minus 04

200E minus 04

250E minus 04

300E minus 04

129E minus 05345E minus 05

613E minus 05

710E minus 05

242E minus 04

386E minus 05

450E minus 05

257E minus 05

322E minus 05

167E minus 05

206E minus 05

234E minus 04

213E minus 04

Figure 8 Distribution of permeability for different samples

Table 4 Sand properties

Physical properties ValueSpecific gravity 2547Cohesion (KPa) 000Angle of internal friction (Degree) 35Modulus elasticity (KPa) 32460Maximum dry density (grcm3) 172Minimum dry density (grcm3) 136Density for 119868

119889

= 75 (grcm3) 1613Permeability (cms) 01Maximum size (mm) 200Minimum size (mm) 0075Uniformity coefficient 119862

119906

4375Coefficient of curvature 119862

119888

097

3 Small Scale Model on Vibrator Table

Physical models with scale parameter equal to 1100 weretested In order to research methodology for this purposesome aspects included characteristic of vibrator table dis-placement transducer data logger sinusoidal motion scaleparameter for static or dynamic condition free vibrationanalysis and physical modeling will be presented In this

study five small scale dams were tested as will be explainedin the next section

31 Vibrator Table In this study vibrating table 24-9112(CN-166) with respect to sinus motion was used Figure 11shows the vibrating desk that was cushioned with steeland seminoiseless electromagnetic vibrator with 3600 vpmoperating frequency In addition it has a separate controllerto vary vibrator amplitude in case of frequency capacitylimit 100Hz Table capacity was equal to 750 lbs (340 kg)Double amplitude range was located at 0002 inch (005mm)to 0015 inch (038mm) Actuator was an electromagneticvibrator over 100 lbs (4530 kg)The table was square in shapeand 30 inch (762mm) The table thickness was 333mm ofsteel In case of weight it was net 555 lbs (252 kg) and shippingwas 605 lbs (274 kg) Figure 11 illustrates the vibrator table forthis study

32 Displacement Transducerand Data Logger Displacementtransducer CDP-D was utilized with respect to dual isolatedIO ports By using transducer one set of cables for input andoutput was connected to the analog measuring instrumentand another set to the digital measuring instrument Withtwo different types of measuring equipment connected tothis transducer simultaneous measurements can be madewithout interference Figure 12(a) shows the displacementtransducer and Figure 12(b) shows the dimensions for trans-ducer CDP-100 Tomeasure displacement at both edges of thecrest in small scale modeling two transducers were installedIn terms of data record data logger or data recorder is anelectronic device that records data over time or in relation tolocation with either a built in instrument or a sensor or viaexternal instruments and sensors

Figure 12(c) illustrates the data logger that was used inthis study Based on device ability results were printed duringthe vibration duration After that results were classified byusing Excel program It should be noted that both transducersas mentioned previously were connected to this data logger(UCAM-70A) in order to record vertical displacement duringthe vibration In addition the sub step of vibration periodwas

6 Shock and Vibration

Stress

Strain

(a)

Stress

Strain

(b)

Figure 9 Damping definition and hysteretic and equivalent bilinear stress-strain relationships for soil (a) stress-strain curves (b) bilinearidealization [23]

400

300

200

100

0

minus100

minus200

minus300

minus400

minus003 minus002 minus001 0 001 002 003

0020

00168

00225Stress (kPa)

Strain

Blue area = 377

Loop area = 850

Damping = 01795

Hysteresis loop-sample 1

(a)

250200150100500

minus50minus100minus150minus200minus250

minus006 minus004 minus002 0 002 004 006

00425

0034

00404

Stress (kPa)

Strain

Hysteresis loop-sample 10

Blue area = 421Loop area = 1197

Damping = 02263

(b)

Figure 10 Estimation of damping ratio (a) sample 1 and (b) sample 10

Figure 11 Vibrator table

equal to two seconds based on device ability with respect toprint

33 Sinusoidal Vibrate Loading There is a mathematicalrelationship between frequency displacement velocity andacceleration for sinusoidalmotion according to considerationof the peak value for them The relationship is such that ifany two of the four variables are known the other two can becalculated Table 5 shows all equations that were provided inthis context [25]

Table 5 Conversion for peak value in sinusoidal motion displace-ment (X) velocity (V) acceleration (A) and frequency (f )

Displacement X Velocity V Acceleration A

Displacement X 119883 = 119883 119883 =119881

2120587119891119883 =

119860

(2120587119891)2

Velocity V 119881 = 2120587119891119883 119881 = 119881 119881 =119860

2120587119891

Acceleration A 119860 = (2120587119891)2

119883 119860 = 2120587119891119881 119860 = 119860

119866 in these formulas is not gravity acceleration It is aconstant for calculation within different systems Respec-tively for metric imperial and Si 119866 is 980665ms23860885827 ins2 and 100ms2

Since themotion is sinusoidal the displacement velocityand acceleration are changing sinusoidal trend Howeverthey are not in the same phase The phase relationshipbetween displacement velocity and acceleration is that veloc-ity is 90∘ out of phase with acceleration and displacement is180∘ out of phase with acceleration

Shock and Vibration 7

(a)

CDP-D

12060110120601D

10

120601E

C A

120601BInputoutput 1Inputoutput 2

2 inputoutput cables

Dimensions

TypeCDP-50-D

A B C D E

165 335 65 5 10

(b)

(c)

Figure 12 Transducer and data logger (a) Displacement transducer CDP-100 (b) dimension of displacement transducer (CDP-100) and (c)data logger UCAM-70A

155

minus5minus15

20100

minus10minus20

25155

minus5minus15minus25

Displacement 13mm peak

Velocity 16336ms peak

Acceleration 2090gn peak

Figure 13 20Hz sinusoidal motion

In other words when displacement is at a maximumvelocity is at a minimum and acceleration is at a maximumIt should be noted that 1 119892

119899

= 980665ms2 = 32174 fts2 =3860886 ins2 Figure 13 shows the example of displacementdistribution with velocity and acceleration while the fre-quency of sinusoidal motion is twenty hertz

34 Scaling Laws In case of the scale parameter the scalefactor can be used according to

119909lowast

=119909119898

119909119901

(2)

The subscript 119898 represents ldquomodelrdquo and the subscript 119901represents ldquoprototyperdquo and 119909lowast represents the scale factor forthe quantity 119909 [26]

k

mx

Figure 14 Mass spring system

Figure 15 Free mesh

The reason for spinning a model on a centrifuge is toenable small scale models to feel the same effective stresses asa full scale prototype This goal can be stated mathematicallyas

1205901015840119909

=1205901015840

119898

1205901015840

119901

= 1 (3)

where the asterisk represents the scaling factor for thequantity 1205901015840

119898

is the effective stress in the model and 1205901015840119901

is theeffective stress in the prototype

8 Shock and Vibration

Nodal solutionStep = 1

UX (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0271E minus 04

Sub = 1X

Y

Z

MN

MX

minus0271E

minus04

minus0210E

minus04

minus0150E

minus04

minus0902Eminus05

minus0301Eminus05

0301Eminus05

0902Eminus05

0150E

minus04

0210E

minus04

0271E

minus04

SMN = minus0271E minus 04

Freq = 0229855

(a)

Nodal solutionStep = 1

Sub = 1

UY (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0126E minus 03

X

Y

Z

MN

MX

minus0971E

minus04

minus0125E

minus03

minus0692E

minus04

minus0413Eminus04

minus0134Eminus04

0145Eminus04

0423E

minus04

0702E

minus04

0981E

minus04

0126E

minus03

SMN = minus0125E minus 03

Freq = 0229855

(b)

X

Y

Z MN

MX

0

0287E

minus04

0575E

minus04

0862Eminus04

0115Eminus03

0144Eminus03

0172Eminus03

0201E

minus03

0230E

minus03

0259E

minus03

Nodal solutionStep = 1

UZ (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0259E minus 03

Sub = 1

Freq = 0229855

(c)

X

Y

Z

MX0

0320E

minus04

0639E

minus04

0959Eminus04

0128Eminus03

0160Eminus03

0192Eminus03

0224E

minus03

0256E

minus03

0288E

minus03

Nodal solutionStep = 1

Sub = 1

USUM (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0288E minus 03

MN

Freq = 0229855

(d)

Figure 16 Mode shape 1 (a) horizontal displacement (b) vertical displacement (c) lateral displacement and (d) total displacement

In soil mechanics the vertical effective stress 1205901015840 forexample is typically calculated by

1205901015840

= 120590119905

minus 119906 (4)

where 120590119905 and 119906 are total stress and pore pressure respectivelyFor a uniform layer with no pore pressure the total verticalstress at a depth119867may be calculated by

120590119905

= 120588119892119867 (5)

where 120588 represents the density of the layer and 119892 representsgravity In the conventional form of centrifugemodeling [26]it is typical that the same materials are used in the model andprototype therefore the densities are the same in model andprototype that is

120588lowast

= 1 (6)

Furthermore in conventional centrifugemodeling all lengthsare scaled by the same factor 119871lowast To produce the same stressin the model as in the prototype we thus require

120588lowast

119892lowast

119867lowast

= 1119892lowast

119871lowast

= 1 (7)

It may be rewritten as

119892lowast

=1

119871lowast

(8)

The above scaling law states that if lengths in the model arereduced by some factor 119899 then gravitational accelerationsmust be increased by the same factor 119899 in order to preserveequal stresses in model and prototype

Shock and Vibration 9

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(a)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(b)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(c)

1650

950

500 5200 500

1000

1000785 Water

Sand

Laterite reinforced

(d)

1650

950

1000

1000785

Laterite

Water

Sand

500 5200 500

(e)

Figure 17 Model introducing ((a) (b) (c) (d) and (e)) for small dam (cm) (119878 = 1100)

For dynamic problems where gravity and accelerationsare important all accelerations must scale as gravity is scaledthat is

119886lowast

= 119892lowast

=1

119871lowast

(9)

Since acceleration has units of 1198711198792 it is required that

119886lowast

=119871lowast

1198792

(10)

Hence it is required that

1

119871lowast

=119871lowast

1198792

or 119879lowast

= 119871lowast

(11)

Frequency has units of inverse of time and velocity has unitsof length per time so for dynamic problems we also obtain

119891lowast

=1

119871lowast

Vlowast =119871lowast

119879lowast

= 1 (12)

For model tests involving dynamics the conflict in time scalefactors may be resolved by scaling the permeability of the soil[26]

35 Free Vibration Analysis In dynamic assessment freevibration analysis is the base of study In fact the distributionof frequency in the different vibrationmode can be computedby the application of modal analysis based on finite-elementmethod (FEM) It is worth mentioning that this analysis isperfectly related to the mass and spring In case of the mass-spring-damper system the first assumption is negligibleabout damping effect Therefore there is not any externalforce on mass in this state The force applied to the massby the spring is proportional to the amount of the springthat is stretched ldquo119909rdquo (it can be assumed that spring isalready compressed due to the weight of the mass) Theproportionality constant (119896) is spring stiffness (see Figure 14)The unit measurement is force divided by distance (kgm)

10 Shock and Vibration

(a) (b)

(c) (d)

Figure 18 Small scale dam (a) Dam perspective with two LVDT (b) soil compaction with roller (c) dam section with index network and(d) dam with tank before vibration

The negative sign indicates that force is always opposingthe motion of the mass attached to it according to thefollowing equation

119865119904

= minus119896119909 (13)

The force generated by the mass is proportional to theacceleration of the mass as given by Newtonrsquos second law ofmotion

sum119865 = 119898119886 = 119898 = 1198981198892

119909

1198891199052

(14)

The sumof the forces on themass then generates this ordinarydifferential equation

119898 + 119896119909 = 0 (15)

Assuming that the initial vibration can be started by stretch-ing and releasing the spring with distance (119860) the solution tothe above equation that describes the motion of mass can beseen in the following equation

119909 (119905) = 119860 cos (2120587119891119899

119905) (16)

This solution shows that it will oscillate with simple harmonicmotion that has amplitude of (119860) and a frequency (119891

119899

) Thenumber (119891

119899

) is called the undamped natural frequency Forthe simple mass-spring system frequency is given by

119891119899

=1

2120587

radic119896

119898 (17)

However the relation between frequency and vibrationperiod is always reverse Consider

119879 =1

119891 (18)

In terms of the measurement unit the vibration periodand frequency were according to seconds and hertz It isworth noting that the dominant frequency is the minimumfrequency to produce maximum vibration period

4 Numerical Analysis

In terms of numerical analysismodal analysis was carried outby using ANSYS program in this study to compute dominantfrequency for small scale model regarding 3D analysis Thisprogram is one of the famous software programs with respectto finite-elementmethod (FEM) In particular this software isone of the universal programs with high level of the ability fordifferent analyses A strong ability to compute free vibrationanalysis is possible with modal analysis [27]

41 Elements and Meshing Process To select element basedon Help menu solid 8 nodes 183 (3D) were used for thispurpose Figure 15 shows the mapped mesh for numericalmodeling In this figure 23956 elements and 35457 nodes inmodels were used for free vibration analysis According tothis condition free vibration analysis to access frequency indifferent vibration modes was carried out as results can bediscussed in the next section

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

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Shock and Vibration

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DistributedSensor Networks

International Journal of

4 Shock and Vibration

12000

10000

8000

6000

4000

2000

0

Sample 2 Sample 6 Sample 7

982937

693668

871086

(a)

12000

10000

8000

6000

4000

2000

0

Sample 3 Sample 8 Sample 9

733618

971862850591

(b)

Sample 4 Sample 10 Sample 11

7000

6000

5000

4000

3000

2000

1000

0

258262

55811

653648

(c)

Sample 5 Sample 12 Sample 13

5000

4000

3000

2000

1000

0

14959

436286

265589

(d)

Figure 5 Distribution of elasticity modulus (Kilo Pascal) for samples

377506

642489

327

593688 747

371 421514

333

61

012345678

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

Figure 6 Distribution of area under the curve of stress-strain basedon unconfined test

with blue and red colors in this figure [24] This ratio can begiven as follows

Damping ratio = 119863 = (1

4120587)

lowast (Loop area

area under stress strain curve)

(1)

However the area under stress strain curve and hysteresisloop area can be computed according to Figure 9 Figure 10shows damping ratio for sample 1 and sample 10 respectivelyIt can be seen that this ratio was 1795 in laterite soil Interms of soil improvement the damping coefficient increasedto 2263 for sample 10 (7 TDA with 3 silica)

After discussing all tests in soil mechanic that werecarried out sample 10 shows the excellent performance inorder to reinforce dam Therefore IDL material was defined

Table 3 Distribution of cohesion and angle of internal friction indifferent samples

Sample Cohesion (KPa) Friction (degree)1 2518 30002 1317 35013 2234 31074 1305 36335 301 29396 1474 3367 1682 33588 1815 33479 1557 363110 2638 321011 3494 285712 2711 286713 1486 3252

by using sample 10 In the physical small dam modeling thismaterial to reinforce dam in different location was used

For small scale modeling the river sand was used forfoundation Table 4 presents sand properties It is importantto note that river sand included uniform size particlesbecause uniformity coefficient was less than five In additioncoefficient of curvature was less than oneThe soil is said to bewell graded if this value lies between one and threeThereforethis type of sand was selected in order to critically conditionfoundation

Shock and Vibration 5

01055

0093301137

0117701566

0207

0111201163

00675

01533 01544

00625

0081

0

005

01

015

02

025

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

mv (average)

(m2M

N)

(a) Coefficient of volume compressibility

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

4416

3395

36076

31893463

8159

3118

28552487

11922659

1596

2311

0102030405060708090

cv (average)

(m2y

ear)

(b) Coefficient of consolidation

Figure 7 Distribution of coefficients in samples for consolidation test (a) Coefficient of volume compressibility and (b) coefficient ofconsolidation

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3Permeability (cms)

000E + 00

500E minus 05

100E minus 04

150E minus 04

200E minus 04

250E minus 04

300E minus 04

129E minus 05345E minus 05

613E minus 05

710E minus 05

242E minus 04

386E minus 05

450E minus 05

257E minus 05

322E minus 05

167E minus 05

206E minus 05

234E minus 04

213E minus 04

Figure 8 Distribution of permeability for different samples

Table 4 Sand properties

Physical properties ValueSpecific gravity 2547Cohesion (KPa) 000Angle of internal friction (Degree) 35Modulus elasticity (KPa) 32460Maximum dry density (grcm3) 172Minimum dry density (grcm3) 136Density for 119868

119889

= 75 (grcm3) 1613Permeability (cms) 01Maximum size (mm) 200Minimum size (mm) 0075Uniformity coefficient 119862

119906

4375Coefficient of curvature 119862

119888

097

3 Small Scale Model on Vibrator Table

Physical models with scale parameter equal to 1100 weretested In order to research methodology for this purposesome aspects included characteristic of vibrator table dis-placement transducer data logger sinusoidal motion scaleparameter for static or dynamic condition free vibrationanalysis and physical modeling will be presented In this

study five small scale dams were tested as will be explainedin the next section

31 Vibrator Table In this study vibrating table 24-9112(CN-166) with respect to sinus motion was used Figure 11shows the vibrating desk that was cushioned with steeland seminoiseless electromagnetic vibrator with 3600 vpmoperating frequency In addition it has a separate controllerto vary vibrator amplitude in case of frequency capacitylimit 100Hz Table capacity was equal to 750 lbs (340 kg)Double amplitude range was located at 0002 inch (005mm)to 0015 inch (038mm) Actuator was an electromagneticvibrator over 100 lbs (4530 kg)The table was square in shapeand 30 inch (762mm) The table thickness was 333mm ofsteel In case of weight it was net 555 lbs (252 kg) and shippingwas 605 lbs (274 kg) Figure 11 illustrates the vibrator table forthis study

32 Displacement Transducerand Data Logger Displacementtransducer CDP-D was utilized with respect to dual isolatedIO ports By using transducer one set of cables for input andoutput was connected to the analog measuring instrumentand another set to the digital measuring instrument Withtwo different types of measuring equipment connected tothis transducer simultaneous measurements can be madewithout interference Figure 12(a) shows the displacementtransducer and Figure 12(b) shows the dimensions for trans-ducer CDP-100 Tomeasure displacement at both edges of thecrest in small scale modeling two transducers were installedIn terms of data record data logger or data recorder is anelectronic device that records data over time or in relation tolocation with either a built in instrument or a sensor or viaexternal instruments and sensors

Figure 12(c) illustrates the data logger that was used inthis study Based on device ability results were printed duringthe vibration duration After that results were classified byusing Excel program It should be noted that both transducersas mentioned previously were connected to this data logger(UCAM-70A) in order to record vertical displacement duringthe vibration In addition the sub step of vibration periodwas

6 Shock and Vibration

Stress

Strain

(a)

Stress

Strain

(b)

Figure 9 Damping definition and hysteretic and equivalent bilinear stress-strain relationships for soil (a) stress-strain curves (b) bilinearidealization [23]

400

300

200

100

0

minus100

minus200

minus300

minus400

minus003 minus002 minus001 0 001 002 003

0020

00168

00225Stress (kPa)

Strain

Blue area = 377

Loop area = 850

Damping = 01795

Hysteresis loop-sample 1

(a)

250200150100500

minus50minus100minus150minus200minus250

minus006 minus004 minus002 0 002 004 006

00425

0034

00404

Stress (kPa)

Strain

Hysteresis loop-sample 10

Blue area = 421Loop area = 1197

Damping = 02263

(b)

Figure 10 Estimation of damping ratio (a) sample 1 and (b) sample 10

Figure 11 Vibrator table

equal to two seconds based on device ability with respect toprint

33 Sinusoidal Vibrate Loading There is a mathematicalrelationship between frequency displacement velocity andacceleration for sinusoidalmotion according to considerationof the peak value for them The relationship is such that ifany two of the four variables are known the other two can becalculated Table 5 shows all equations that were provided inthis context [25]

Table 5 Conversion for peak value in sinusoidal motion displace-ment (X) velocity (V) acceleration (A) and frequency (f )

Displacement X Velocity V Acceleration A

Displacement X 119883 = 119883 119883 =119881

2120587119891119883 =

119860

(2120587119891)2

Velocity V 119881 = 2120587119891119883 119881 = 119881 119881 =119860

2120587119891

Acceleration A 119860 = (2120587119891)2

119883 119860 = 2120587119891119881 119860 = 119860

119866 in these formulas is not gravity acceleration It is aconstant for calculation within different systems Respec-tively for metric imperial and Si 119866 is 980665ms23860885827 ins2 and 100ms2

Since themotion is sinusoidal the displacement velocityand acceleration are changing sinusoidal trend Howeverthey are not in the same phase The phase relationshipbetween displacement velocity and acceleration is that veloc-ity is 90∘ out of phase with acceleration and displacement is180∘ out of phase with acceleration

Shock and Vibration 7

(a)

CDP-D

12060110120601D

10

120601E

C A

120601BInputoutput 1Inputoutput 2

2 inputoutput cables

Dimensions

TypeCDP-50-D

A B C D E

165 335 65 5 10

(b)

(c)

Figure 12 Transducer and data logger (a) Displacement transducer CDP-100 (b) dimension of displacement transducer (CDP-100) and (c)data logger UCAM-70A

155

minus5minus15

20100

minus10minus20

25155

minus5minus15minus25

Displacement 13mm peak

Velocity 16336ms peak

Acceleration 2090gn peak

Figure 13 20Hz sinusoidal motion

In other words when displacement is at a maximumvelocity is at a minimum and acceleration is at a maximumIt should be noted that 1 119892

119899

= 980665ms2 = 32174 fts2 =3860886 ins2 Figure 13 shows the example of displacementdistribution with velocity and acceleration while the fre-quency of sinusoidal motion is twenty hertz

34 Scaling Laws In case of the scale parameter the scalefactor can be used according to

119909lowast

=119909119898

119909119901

(2)

The subscript 119898 represents ldquomodelrdquo and the subscript 119901represents ldquoprototyperdquo and 119909lowast represents the scale factor forthe quantity 119909 [26]

k

mx

Figure 14 Mass spring system

Figure 15 Free mesh

The reason for spinning a model on a centrifuge is toenable small scale models to feel the same effective stresses asa full scale prototype This goal can be stated mathematicallyas

1205901015840119909

=1205901015840

119898

1205901015840

119901

= 1 (3)

where the asterisk represents the scaling factor for thequantity 1205901015840

119898

is the effective stress in the model and 1205901015840119901

is theeffective stress in the prototype

8 Shock and Vibration

Nodal solutionStep = 1

UX (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0271E minus 04

Sub = 1X

Y

Z

MN

MX

minus0271E

minus04

minus0210E

minus04

minus0150E

minus04

minus0902Eminus05

minus0301Eminus05

0301Eminus05

0902Eminus05

0150E

minus04

0210E

minus04

0271E

minus04

SMN = minus0271E minus 04

Freq = 0229855

(a)

Nodal solutionStep = 1

Sub = 1

UY (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0126E minus 03

X

Y

Z

MN

MX

minus0971E

minus04

minus0125E

minus03

minus0692E

minus04

minus0413Eminus04

minus0134Eminus04

0145Eminus04

0423E

minus04

0702E

minus04

0981E

minus04

0126E

minus03

SMN = minus0125E minus 03

Freq = 0229855

(b)

X

Y

Z MN

MX

0

0287E

minus04

0575E

minus04

0862Eminus04

0115Eminus03

0144Eminus03

0172Eminus03

0201E

minus03

0230E

minus03

0259E

minus03

Nodal solutionStep = 1

UZ (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0259E minus 03

Sub = 1

Freq = 0229855

(c)

X

Y

Z

MX0

0320E

minus04

0639E

minus04

0959Eminus04

0128Eminus03

0160Eminus03

0192Eminus03

0224E

minus03

0256E

minus03

0288E

minus03

Nodal solutionStep = 1

Sub = 1

USUM (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0288E minus 03

MN

Freq = 0229855

(d)

Figure 16 Mode shape 1 (a) horizontal displacement (b) vertical displacement (c) lateral displacement and (d) total displacement

In soil mechanics the vertical effective stress 1205901015840 forexample is typically calculated by

1205901015840

= 120590119905

minus 119906 (4)

where 120590119905 and 119906 are total stress and pore pressure respectivelyFor a uniform layer with no pore pressure the total verticalstress at a depth119867may be calculated by

120590119905

= 120588119892119867 (5)

where 120588 represents the density of the layer and 119892 representsgravity In the conventional form of centrifugemodeling [26]it is typical that the same materials are used in the model andprototype therefore the densities are the same in model andprototype that is

120588lowast

= 1 (6)

Furthermore in conventional centrifugemodeling all lengthsare scaled by the same factor 119871lowast To produce the same stressin the model as in the prototype we thus require

120588lowast

119892lowast

119867lowast

= 1119892lowast

119871lowast

= 1 (7)

It may be rewritten as

119892lowast

=1

119871lowast

(8)

The above scaling law states that if lengths in the model arereduced by some factor 119899 then gravitational accelerationsmust be increased by the same factor 119899 in order to preserveequal stresses in model and prototype

Shock and Vibration 9

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(a)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(b)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(c)

1650

950

500 5200 500

1000

1000785 Water

Sand

Laterite reinforced

(d)

1650

950

1000

1000785

Laterite

Water

Sand

500 5200 500

(e)

Figure 17 Model introducing ((a) (b) (c) (d) and (e)) for small dam (cm) (119878 = 1100)

For dynamic problems where gravity and accelerationsare important all accelerations must scale as gravity is scaledthat is

119886lowast

= 119892lowast

=1

119871lowast

(9)

Since acceleration has units of 1198711198792 it is required that

119886lowast

=119871lowast

1198792

(10)

Hence it is required that

1

119871lowast

=119871lowast

1198792

or 119879lowast

= 119871lowast

(11)

Frequency has units of inverse of time and velocity has unitsof length per time so for dynamic problems we also obtain

119891lowast

=1

119871lowast

Vlowast =119871lowast

119879lowast

= 1 (12)

For model tests involving dynamics the conflict in time scalefactors may be resolved by scaling the permeability of the soil[26]

35 Free Vibration Analysis In dynamic assessment freevibration analysis is the base of study In fact the distributionof frequency in the different vibrationmode can be computedby the application of modal analysis based on finite-elementmethod (FEM) It is worth mentioning that this analysis isperfectly related to the mass and spring In case of the mass-spring-damper system the first assumption is negligibleabout damping effect Therefore there is not any externalforce on mass in this state The force applied to the massby the spring is proportional to the amount of the springthat is stretched ldquo119909rdquo (it can be assumed that spring isalready compressed due to the weight of the mass) Theproportionality constant (119896) is spring stiffness (see Figure 14)The unit measurement is force divided by distance (kgm)

10 Shock and Vibration

(a) (b)

(c) (d)

Figure 18 Small scale dam (a) Dam perspective with two LVDT (b) soil compaction with roller (c) dam section with index network and(d) dam with tank before vibration

The negative sign indicates that force is always opposingthe motion of the mass attached to it according to thefollowing equation

119865119904

= minus119896119909 (13)

The force generated by the mass is proportional to theacceleration of the mass as given by Newtonrsquos second law ofmotion

sum119865 = 119898119886 = 119898 = 1198981198892

119909

1198891199052

(14)

The sumof the forces on themass then generates this ordinarydifferential equation

119898 + 119896119909 = 0 (15)

Assuming that the initial vibration can be started by stretch-ing and releasing the spring with distance (119860) the solution tothe above equation that describes the motion of mass can beseen in the following equation

119909 (119905) = 119860 cos (2120587119891119899

119905) (16)

This solution shows that it will oscillate with simple harmonicmotion that has amplitude of (119860) and a frequency (119891

119899

) Thenumber (119891

119899

) is called the undamped natural frequency Forthe simple mass-spring system frequency is given by

119891119899

=1

2120587

radic119896

119898 (17)

However the relation between frequency and vibrationperiod is always reverse Consider

119879 =1

119891 (18)

In terms of the measurement unit the vibration periodand frequency were according to seconds and hertz It isworth noting that the dominant frequency is the minimumfrequency to produce maximum vibration period

4 Numerical Analysis

In terms of numerical analysismodal analysis was carried outby using ANSYS program in this study to compute dominantfrequency for small scale model regarding 3D analysis Thisprogram is one of the famous software programs with respectto finite-elementmethod (FEM) In particular this software isone of the universal programs with high level of the ability fordifferent analyses A strong ability to compute free vibrationanalysis is possible with modal analysis [27]

41 Elements and Meshing Process To select element basedon Help menu solid 8 nodes 183 (3D) were used for thispurpose Figure 15 shows the mapped mesh for numericalmodeling In this figure 23956 elements and 35457 nodes inmodels were used for free vibration analysis According tothis condition free vibration analysis to access frequency indifferent vibration modes was carried out as results can bediscussed in the next section

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

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Submit your manuscripts athttpwwwhindawicom

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Shock and Vibration

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Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

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Chemical EngineeringInternational Journal of Antennas and

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Navigation and Observation

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DistributedSensor Networks

International Journal of

Shock and Vibration 5

01055

0093301137

0117701566

0207

0111201163

00675

01533 01544

00625

0081

0

005

01

015

02

025

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

mv (average)

(m2M

N)

(a) Coefficient of volume compressibility

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3

4416

3395

36076

31893463

8159

3118

28552487

11922659

1596

2311

0102030405060708090

cv (average)

(m2y

ear)

(b) Coefficient of consolidation

Figure 7 Distribution of coefficients in samples for consolidation test (a) Coefficient of volume compressibility and (b) coefficient ofconsolidation

Sam

ple 1

Sam

ple 2

Sam

ple 3

Sam

ple 4

Sam

ple 5

Sam

ple 6

Sam

ple 7

Sam

ple 8

Sam

ple 9

Sam

ple 1

0

Sam

ple 1

1

Sam

ple 1

2

Sam

ple 1

3Permeability (cms)

000E + 00

500E minus 05

100E minus 04

150E minus 04

200E minus 04

250E minus 04

300E minus 04

129E minus 05345E minus 05

613E minus 05

710E minus 05

242E minus 04

386E minus 05

450E minus 05

257E minus 05

322E minus 05

167E minus 05

206E minus 05

234E minus 04

213E minus 04

Figure 8 Distribution of permeability for different samples

Table 4 Sand properties

Physical properties ValueSpecific gravity 2547Cohesion (KPa) 000Angle of internal friction (Degree) 35Modulus elasticity (KPa) 32460Maximum dry density (grcm3) 172Minimum dry density (grcm3) 136Density for 119868

119889

= 75 (grcm3) 1613Permeability (cms) 01Maximum size (mm) 200Minimum size (mm) 0075Uniformity coefficient 119862

119906

4375Coefficient of curvature 119862

119888

097

3 Small Scale Model on Vibrator Table

Physical models with scale parameter equal to 1100 weretested In order to research methodology for this purposesome aspects included characteristic of vibrator table dis-placement transducer data logger sinusoidal motion scaleparameter for static or dynamic condition free vibrationanalysis and physical modeling will be presented In this

study five small scale dams were tested as will be explainedin the next section

31 Vibrator Table In this study vibrating table 24-9112(CN-166) with respect to sinus motion was used Figure 11shows the vibrating desk that was cushioned with steeland seminoiseless electromagnetic vibrator with 3600 vpmoperating frequency In addition it has a separate controllerto vary vibrator amplitude in case of frequency capacitylimit 100Hz Table capacity was equal to 750 lbs (340 kg)Double amplitude range was located at 0002 inch (005mm)to 0015 inch (038mm) Actuator was an electromagneticvibrator over 100 lbs (4530 kg)The table was square in shapeand 30 inch (762mm) The table thickness was 333mm ofsteel In case of weight it was net 555 lbs (252 kg) and shippingwas 605 lbs (274 kg) Figure 11 illustrates the vibrator table forthis study

32 Displacement Transducerand Data Logger Displacementtransducer CDP-D was utilized with respect to dual isolatedIO ports By using transducer one set of cables for input andoutput was connected to the analog measuring instrumentand another set to the digital measuring instrument Withtwo different types of measuring equipment connected tothis transducer simultaneous measurements can be madewithout interference Figure 12(a) shows the displacementtransducer and Figure 12(b) shows the dimensions for trans-ducer CDP-100 Tomeasure displacement at both edges of thecrest in small scale modeling two transducers were installedIn terms of data record data logger or data recorder is anelectronic device that records data over time or in relation tolocation with either a built in instrument or a sensor or viaexternal instruments and sensors

Figure 12(c) illustrates the data logger that was used inthis study Based on device ability results were printed duringthe vibration duration After that results were classified byusing Excel program It should be noted that both transducersas mentioned previously were connected to this data logger(UCAM-70A) in order to record vertical displacement duringthe vibration In addition the sub step of vibration periodwas

6 Shock and Vibration

Stress

Strain

(a)

Stress

Strain

(b)

Figure 9 Damping definition and hysteretic and equivalent bilinear stress-strain relationships for soil (a) stress-strain curves (b) bilinearidealization [23]

400

300

200

100

0

minus100

minus200

minus300

minus400

minus003 minus002 minus001 0 001 002 003

0020

00168

00225Stress (kPa)

Strain

Blue area = 377

Loop area = 850

Damping = 01795

Hysteresis loop-sample 1

(a)

250200150100500

minus50minus100minus150minus200minus250

minus006 minus004 minus002 0 002 004 006

00425

0034

00404

Stress (kPa)

Strain

Hysteresis loop-sample 10

Blue area = 421Loop area = 1197

Damping = 02263

(b)

Figure 10 Estimation of damping ratio (a) sample 1 and (b) sample 10

Figure 11 Vibrator table

equal to two seconds based on device ability with respect toprint

33 Sinusoidal Vibrate Loading There is a mathematicalrelationship between frequency displacement velocity andacceleration for sinusoidalmotion according to considerationof the peak value for them The relationship is such that ifany two of the four variables are known the other two can becalculated Table 5 shows all equations that were provided inthis context [25]

Table 5 Conversion for peak value in sinusoidal motion displace-ment (X) velocity (V) acceleration (A) and frequency (f )

Displacement X Velocity V Acceleration A

Displacement X 119883 = 119883 119883 =119881

2120587119891119883 =

119860

(2120587119891)2

Velocity V 119881 = 2120587119891119883 119881 = 119881 119881 =119860

2120587119891

Acceleration A 119860 = (2120587119891)2

119883 119860 = 2120587119891119881 119860 = 119860

119866 in these formulas is not gravity acceleration It is aconstant for calculation within different systems Respec-tively for metric imperial and Si 119866 is 980665ms23860885827 ins2 and 100ms2

Since themotion is sinusoidal the displacement velocityand acceleration are changing sinusoidal trend Howeverthey are not in the same phase The phase relationshipbetween displacement velocity and acceleration is that veloc-ity is 90∘ out of phase with acceleration and displacement is180∘ out of phase with acceleration

Shock and Vibration 7

(a)

CDP-D

12060110120601D

10

120601E

C A

120601BInputoutput 1Inputoutput 2

2 inputoutput cables

Dimensions

TypeCDP-50-D

A B C D E

165 335 65 5 10

(b)

(c)

Figure 12 Transducer and data logger (a) Displacement transducer CDP-100 (b) dimension of displacement transducer (CDP-100) and (c)data logger UCAM-70A

155

minus5minus15

20100

minus10minus20

25155

minus5minus15minus25

Displacement 13mm peak

Velocity 16336ms peak

Acceleration 2090gn peak

Figure 13 20Hz sinusoidal motion

In other words when displacement is at a maximumvelocity is at a minimum and acceleration is at a maximumIt should be noted that 1 119892

119899

= 980665ms2 = 32174 fts2 =3860886 ins2 Figure 13 shows the example of displacementdistribution with velocity and acceleration while the fre-quency of sinusoidal motion is twenty hertz

34 Scaling Laws In case of the scale parameter the scalefactor can be used according to

119909lowast

=119909119898

119909119901

(2)

The subscript 119898 represents ldquomodelrdquo and the subscript 119901represents ldquoprototyperdquo and 119909lowast represents the scale factor forthe quantity 119909 [26]

k

mx

Figure 14 Mass spring system

Figure 15 Free mesh

The reason for spinning a model on a centrifuge is toenable small scale models to feel the same effective stresses asa full scale prototype This goal can be stated mathematicallyas

1205901015840119909

=1205901015840

119898

1205901015840

119901

= 1 (3)

where the asterisk represents the scaling factor for thequantity 1205901015840

119898

is the effective stress in the model and 1205901015840119901

is theeffective stress in the prototype

8 Shock and Vibration

Nodal solutionStep = 1

UX (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0271E minus 04

Sub = 1X

Y

Z

MN

MX

minus0271E

minus04

minus0210E

minus04

minus0150E

minus04

minus0902Eminus05

minus0301Eminus05

0301Eminus05

0902Eminus05

0150E

minus04

0210E

minus04

0271E

minus04

SMN = minus0271E minus 04

Freq = 0229855

(a)

Nodal solutionStep = 1

Sub = 1

UY (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0126E minus 03

X

Y

Z

MN

MX

minus0971E

minus04

minus0125E

minus03

minus0692E

minus04

minus0413Eminus04

minus0134Eminus04

0145Eminus04

0423E

minus04

0702E

minus04

0981E

minus04

0126E

minus03

SMN = minus0125E minus 03

Freq = 0229855

(b)

X

Y

Z MN

MX

0

0287E

minus04

0575E

minus04

0862Eminus04

0115Eminus03

0144Eminus03

0172Eminus03

0201E

minus03

0230E

minus03

0259E

minus03

Nodal solutionStep = 1

UZ (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0259E minus 03

Sub = 1

Freq = 0229855

(c)

X

Y

Z

MX0

0320E

minus04

0639E

minus04

0959Eminus04

0128Eminus03

0160Eminus03

0192Eminus03

0224E

minus03

0256E

minus03

0288E

minus03

Nodal solutionStep = 1

Sub = 1

USUM (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0288E minus 03

MN

Freq = 0229855

(d)

Figure 16 Mode shape 1 (a) horizontal displacement (b) vertical displacement (c) lateral displacement and (d) total displacement

In soil mechanics the vertical effective stress 1205901015840 forexample is typically calculated by

1205901015840

= 120590119905

minus 119906 (4)

where 120590119905 and 119906 are total stress and pore pressure respectivelyFor a uniform layer with no pore pressure the total verticalstress at a depth119867may be calculated by

120590119905

= 120588119892119867 (5)

where 120588 represents the density of the layer and 119892 representsgravity In the conventional form of centrifugemodeling [26]it is typical that the same materials are used in the model andprototype therefore the densities are the same in model andprototype that is

120588lowast

= 1 (6)

Furthermore in conventional centrifugemodeling all lengthsare scaled by the same factor 119871lowast To produce the same stressin the model as in the prototype we thus require

120588lowast

119892lowast

119867lowast

= 1119892lowast

119871lowast

= 1 (7)

It may be rewritten as

119892lowast

=1

119871lowast

(8)

The above scaling law states that if lengths in the model arereduced by some factor 119899 then gravitational accelerationsmust be increased by the same factor 119899 in order to preserveequal stresses in model and prototype

Shock and Vibration 9

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(a)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(b)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(c)

1650

950

500 5200 500

1000

1000785 Water

Sand

Laterite reinforced

(d)

1650

950

1000

1000785

Laterite

Water

Sand

500 5200 500

(e)

Figure 17 Model introducing ((a) (b) (c) (d) and (e)) for small dam (cm) (119878 = 1100)

For dynamic problems where gravity and accelerationsare important all accelerations must scale as gravity is scaledthat is

119886lowast

= 119892lowast

=1

119871lowast

(9)

Since acceleration has units of 1198711198792 it is required that

119886lowast

=119871lowast

1198792

(10)

Hence it is required that

1

119871lowast

=119871lowast

1198792

or 119879lowast

= 119871lowast

(11)

Frequency has units of inverse of time and velocity has unitsof length per time so for dynamic problems we also obtain

119891lowast

=1

119871lowast

Vlowast =119871lowast

119879lowast

= 1 (12)

For model tests involving dynamics the conflict in time scalefactors may be resolved by scaling the permeability of the soil[26]

35 Free Vibration Analysis In dynamic assessment freevibration analysis is the base of study In fact the distributionof frequency in the different vibrationmode can be computedby the application of modal analysis based on finite-elementmethod (FEM) It is worth mentioning that this analysis isperfectly related to the mass and spring In case of the mass-spring-damper system the first assumption is negligibleabout damping effect Therefore there is not any externalforce on mass in this state The force applied to the massby the spring is proportional to the amount of the springthat is stretched ldquo119909rdquo (it can be assumed that spring isalready compressed due to the weight of the mass) Theproportionality constant (119896) is spring stiffness (see Figure 14)The unit measurement is force divided by distance (kgm)

10 Shock and Vibration

(a) (b)

(c) (d)

Figure 18 Small scale dam (a) Dam perspective with two LVDT (b) soil compaction with roller (c) dam section with index network and(d) dam with tank before vibration

The negative sign indicates that force is always opposingthe motion of the mass attached to it according to thefollowing equation

119865119904

= minus119896119909 (13)

The force generated by the mass is proportional to theacceleration of the mass as given by Newtonrsquos second law ofmotion

sum119865 = 119898119886 = 119898 = 1198981198892

119909

1198891199052

(14)

The sumof the forces on themass then generates this ordinarydifferential equation

119898 + 119896119909 = 0 (15)

Assuming that the initial vibration can be started by stretch-ing and releasing the spring with distance (119860) the solution tothe above equation that describes the motion of mass can beseen in the following equation

119909 (119905) = 119860 cos (2120587119891119899

119905) (16)

This solution shows that it will oscillate with simple harmonicmotion that has amplitude of (119860) and a frequency (119891

119899

) Thenumber (119891

119899

) is called the undamped natural frequency Forthe simple mass-spring system frequency is given by

119891119899

=1

2120587

radic119896

119898 (17)

However the relation between frequency and vibrationperiod is always reverse Consider

119879 =1

119891 (18)

In terms of the measurement unit the vibration periodand frequency were according to seconds and hertz It isworth noting that the dominant frequency is the minimumfrequency to produce maximum vibration period

4 Numerical Analysis

In terms of numerical analysismodal analysis was carried outby using ANSYS program in this study to compute dominantfrequency for small scale model regarding 3D analysis Thisprogram is one of the famous software programs with respectto finite-elementmethod (FEM) In particular this software isone of the universal programs with high level of the ability fordifferent analyses A strong ability to compute free vibrationanalysis is possible with modal analysis [27]

41 Elements and Meshing Process To select element basedon Help menu solid 8 nodes 183 (3D) were used for thispurpose Figure 15 shows the mapped mesh for numericalmodeling In this figure 23956 elements and 35457 nodes inmodels were used for free vibration analysis According tothis condition free vibration analysis to access frequency indifferent vibration modes was carried out as results can bediscussed in the next section

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

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Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

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Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

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International Journal of

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Navigation and Observation

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DistributedSensor Networks

International Journal of

6 Shock and Vibration

Stress

Strain

(a)

Stress

Strain

(b)

Figure 9 Damping definition and hysteretic and equivalent bilinear stress-strain relationships for soil (a) stress-strain curves (b) bilinearidealization [23]

400

300

200

100

0

minus100

minus200

minus300

minus400

minus003 minus002 minus001 0 001 002 003

0020

00168

00225Stress (kPa)

Strain

Blue area = 377

Loop area = 850

Damping = 01795

Hysteresis loop-sample 1

(a)

250200150100500

minus50minus100minus150minus200minus250

minus006 minus004 minus002 0 002 004 006

00425

0034

00404

Stress (kPa)

Strain

Hysteresis loop-sample 10

Blue area = 421Loop area = 1197

Damping = 02263

(b)

Figure 10 Estimation of damping ratio (a) sample 1 and (b) sample 10

Figure 11 Vibrator table

equal to two seconds based on device ability with respect toprint

33 Sinusoidal Vibrate Loading There is a mathematicalrelationship between frequency displacement velocity andacceleration for sinusoidalmotion according to considerationof the peak value for them The relationship is such that ifany two of the four variables are known the other two can becalculated Table 5 shows all equations that were provided inthis context [25]

Table 5 Conversion for peak value in sinusoidal motion displace-ment (X) velocity (V) acceleration (A) and frequency (f )

Displacement X Velocity V Acceleration A

Displacement X 119883 = 119883 119883 =119881

2120587119891119883 =

119860

(2120587119891)2

Velocity V 119881 = 2120587119891119883 119881 = 119881 119881 =119860

2120587119891

Acceleration A 119860 = (2120587119891)2

119883 119860 = 2120587119891119881 119860 = 119860

119866 in these formulas is not gravity acceleration It is aconstant for calculation within different systems Respec-tively for metric imperial and Si 119866 is 980665ms23860885827 ins2 and 100ms2

Since themotion is sinusoidal the displacement velocityand acceleration are changing sinusoidal trend Howeverthey are not in the same phase The phase relationshipbetween displacement velocity and acceleration is that veloc-ity is 90∘ out of phase with acceleration and displacement is180∘ out of phase with acceleration

Shock and Vibration 7

(a)

CDP-D

12060110120601D

10

120601E

C A

120601BInputoutput 1Inputoutput 2

2 inputoutput cables

Dimensions

TypeCDP-50-D

A B C D E

165 335 65 5 10

(b)

(c)

Figure 12 Transducer and data logger (a) Displacement transducer CDP-100 (b) dimension of displacement transducer (CDP-100) and (c)data logger UCAM-70A

155

minus5minus15

20100

minus10minus20

25155

minus5minus15minus25

Displacement 13mm peak

Velocity 16336ms peak

Acceleration 2090gn peak

Figure 13 20Hz sinusoidal motion

In other words when displacement is at a maximumvelocity is at a minimum and acceleration is at a maximumIt should be noted that 1 119892

119899

= 980665ms2 = 32174 fts2 =3860886 ins2 Figure 13 shows the example of displacementdistribution with velocity and acceleration while the fre-quency of sinusoidal motion is twenty hertz

34 Scaling Laws In case of the scale parameter the scalefactor can be used according to

119909lowast

=119909119898

119909119901

(2)

The subscript 119898 represents ldquomodelrdquo and the subscript 119901represents ldquoprototyperdquo and 119909lowast represents the scale factor forthe quantity 119909 [26]

k

mx

Figure 14 Mass spring system

Figure 15 Free mesh

The reason for spinning a model on a centrifuge is toenable small scale models to feel the same effective stresses asa full scale prototype This goal can be stated mathematicallyas

1205901015840119909

=1205901015840

119898

1205901015840

119901

= 1 (3)

where the asterisk represents the scaling factor for thequantity 1205901015840

119898

is the effective stress in the model and 1205901015840119901

is theeffective stress in the prototype

8 Shock and Vibration

Nodal solutionStep = 1

UX (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0271E minus 04

Sub = 1X

Y

Z

MN

MX

minus0271E

minus04

minus0210E

minus04

minus0150E

minus04

minus0902Eminus05

minus0301Eminus05

0301Eminus05

0902Eminus05

0150E

minus04

0210E

minus04

0271E

minus04

SMN = minus0271E minus 04

Freq = 0229855

(a)

Nodal solutionStep = 1

Sub = 1

UY (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0126E minus 03

X

Y

Z

MN

MX

minus0971E

minus04

minus0125E

minus03

minus0692E

minus04

minus0413Eminus04

minus0134Eminus04

0145Eminus04

0423E

minus04

0702E

minus04

0981E

minus04

0126E

minus03

SMN = minus0125E minus 03

Freq = 0229855

(b)

X

Y

Z MN

MX

0

0287E

minus04

0575E

minus04

0862Eminus04

0115Eminus03

0144Eminus03

0172Eminus03

0201E

minus03

0230E

minus03

0259E

minus03

Nodal solutionStep = 1

UZ (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0259E minus 03

Sub = 1

Freq = 0229855

(c)

X

Y

Z

MX0

0320E

minus04

0639E

minus04

0959Eminus04

0128Eminus03

0160Eminus03

0192Eminus03

0224E

minus03

0256E

minus03

0288E

minus03

Nodal solutionStep = 1

Sub = 1

USUM (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0288E minus 03

MN

Freq = 0229855

(d)

Figure 16 Mode shape 1 (a) horizontal displacement (b) vertical displacement (c) lateral displacement and (d) total displacement

In soil mechanics the vertical effective stress 1205901015840 forexample is typically calculated by

1205901015840

= 120590119905

minus 119906 (4)

where 120590119905 and 119906 are total stress and pore pressure respectivelyFor a uniform layer with no pore pressure the total verticalstress at a depth119867may be calculated by

120590119905

= 120588119892119867 (5)

where 120588 represents the density of the layer and 119892 representsgravity In the conventional form of centrifugemodeling [26]it is typical that the same materials are used in the model andprototype therefore the densities are the same in model andprototype that is

120588lowast

= 1 (6)

Furthermore in conventional centrifugemodeling all lengthsare scaled by the same factor 119871lowast To produce the same stressin the model as in the prototype we thus require

120588lowast

119892lowast

119867lowast

= 1119892lowast

119871lowast

= 1 (7)

It may be rewritten as

119892lowast

=1

119871lowast

(8)

The above scaling law states that if lengths in the model arereduced by some factor 119899 then gravitational accelerationsmust be increased by the same factor 119899 in order to preserveequal stresses in model and prototype

Shock and Vibration 9

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(a)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(b)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(c)

1650

950

500 5200 500

1000

1000785 Water

Sand

Laterite reinforced

(d)

1650

950

1000

1000785

Laterite

Water

Sand

500 5200 500

(e)

Figure 17 Model introducing ((a) (b) (c) (d) and (e)) for small dam (cm) (119878 = 1100)

For dynamic problems where gravity and accelerationsare important all accelerations must scale as gravity is scaledthat is

119886lowast

= 119892lowast

=1

119871lowast

(9)

Since acceleration has units of 1198711198792 it is required that

119886lowast

=119871lowast

1198792

(10)

Hence it is required that

1

119871lowast

=119871lowast

1198792

or 119879lowast

= 119871lowast

(11)

Frequency has units of inverse of time and velocity has unitsof length per time so for dynamic problems we also obtain

119891lowast

=1

119871lowast

Vlowast =119871lowast

119879lowast

= 1 (12)

For model tests involving dynamics the conflict in time scalefactors may be resolved by scaling the permeability of the soil[26]

35 Free Vibration Analysis In dynamic assessment freevibration analysis is the base of study In fact the distributionof frequency in the different vibrationmode can be computedby the application of modal analysis based on finite-elementmethod (FEM) It is worth mentioning that this analysis isperfectly related to the mass and spring In case of the mass-spring-damper system the first assumption is negligibleabout damping effect Therefore there is not any externalforce on mass in this state The force applied to the massby the spring is proportional to the amount of the springthat is stretched ldquo119909rdquo (it can be assumed that spring isalready compressed due to the weight of the mass) Theproportionality constant (119896) is spring stiffness (see Figure 14)The unit measurement is force divided by distance (kgm)

10 Shock and Vibration

(a) (b)

(c) (d)

Figure 18 Small scale dam (a) Dam perspective with two LVDT (b) soil compaction with roller (c) dam section with index network and(d) dam with tank before vibration

The negative sign indicates that force is always opposingthe motion of the mass attached to it according to thefollowing equation

119865119904

= minus119896119909 (13)

The force generated by the mass is proportional to theacceleration of the mass as given by Newtonrsquos second law ofmotion

sum119865 = 119898119886 = 119898 = 1198981198892

119909

1198891199052

(14)

The sumof the forces on themass then generates this ordinarydifferential equation

119898 + 119896119909 = 0 (15)

Assuming that the initial vibration can be started by stretch-ing and releasing the spring with distance (119860) the solution tothe above equation that describes the motion of mass can beseen in the following equation

119909 (119905) = 119860 cos (2120587119891119899

119905) (16)

This solution shows that it will oscillate with simple harmonicmotion that has amplitude of (119860) and a frequency (119891

119899

) Thenumber (119891

119899

) is called the undamped natural frequency Forthe simple mass-spring system frequency is given by

119891119899

=1

2120587

radic119896

119898 (17)

However the relation between frequency and vibrationperiod is always reverse Consider

119879 =1

119891 (18)

In terms of the measurement unit the vibration periodand frequency were according to seconds and hertz It isworth noting that the dominant frequency is the minimumfrequency to produce maximum vibration period

4 Numerical Analysis

In terms of numerical analysismodal analysis was carried outby using ANSYS program in this study to compute dominantfrequency for small scale model regarding 3D analysis Thisprogram is one of the famous software programs with respectto finite-elementmethod (FEM) In particular this software isone of the universal programs with high level of the ability fordifferent analyses A strong ability to compute free vibrationanalysis is possible with modal analysis [27]

41 Elements and Meshing Process To select element basedon Help menu solid 8 nodes 183 (3D) were used for thispurpose Figure 15 shows the mapped mesh for numericalmodeling In this figure 23956 elements and 35457 nodes inmodels were used for free vibration analysis According tothis condition free vibration analysis to access frequency indifferent vibration modes was carried out as results can bediscussed in the next section

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

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Shock and Vibration

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DistributedSensor Networks

International Journal of

Shock and Vibration 7

(a)

CDP-D

12060110120601D

10

120601E

C A

120601BInputoutput 1Inputoutput 2

2 inputoutput cables

Dimensions

TypeCDP-50-D

A B C D E

165 335 65 5 10

(b)

(c)

Figure 12 Transducer and data logger (a) Displacement transducer CDP-100 (b) dimension of displacement transducer (CDP-100) and (c)data logger UCAM-70A

155

minus5minus15

20100

minus10minus20

25155

minus5minus15minus25

Displacement 13mm peak

Velocity 16336ms peak

Acceleration 2090gn peak

Figure 13 20Hz sinusoidal motion

In other words when displacement is at a maximumvelocity is at a minimum and acceleration is at a maximumIt should be noted that 1 119892

119899

= 980665ms2 = 32174 fts2 =3860886 ins2 Figure 13 shows the example of displacementdistribution with velocity and acceleration while the fre-quency of sinusoidal motion is twenty hertz

34 Scaling Laws In case of the scale parameter the scalefactor can be used according to

119909lowast

=119909119898

119909119901

(2)

The subscript 119898 represents ldquomodelrdquo and the subscript 119901represents ldquoprototyperdquo and 119909lowast represents the scale factor forthe quantity 119909 [26]

k

mx

Figure 14 Mass spring system

Figure 15 Free mesh

The reason for spinning a model on a centrifuge is toenable small scale models to feel the same effective stresses asa full scale prototype This goal can be stated mathematicallyas

1205901015840119909

=1205901015840

119898

1205901015840

119901

= 1 (3)

where the asterisk represents the scaling factor for thequantity 1205901015840

119898

is the effective stress in the model and 1205901015840119901

is theeffective stress in the prototype

8 Shock and Vibration

Nodal solutionStep = 1

UX (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0271E minus 04

Sub = 1X

Y

Z

MN

MX

minus0271E

minus04

minus0210E

minus04

minus0150E

minus04

minus0902Eminus05

minus0301Eminus05

0301Eminus05

0902Eminus05

0150E

minus04

0210E

minus04

0271E

minus04

SMN = minus0271E minus 04

Freq = 0229855

(a)

Nodal solutionStep = 1

Sub = 1

UY (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0126E minus 03

X

Y

Z

MN

MX

minus0971E

minus04

minus0125E

minus03

minus0692E

minus04

minus0413Eminus04

minus0134Eminus04

0145Eminus04

0423E

minus04

0702E

minus04

0981E

minus04

0126E

minus03

SMN = minus0125E minus 03

Freq = 0229855

(b)

X

Y

Z MN

MX

0

0287E

minus04

0575E

minus04

0862Eminus04

0115Eminus03

0144Eminus03

0172Eminus03

0201E

minus03

0230E

minus03

0259E

minus03

Nodal solutionStep = 1

UZ (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0259E minus 03

Sub = 1

Freq = 0229855

(c)

X

Y

Z

MX0

0320E

minus04

0639E

minus04

0959Eminus04

0128Eminus03

0160Eminus03

0192Eminus03

0224E

minus03

0256E

minus03

0288E

minus03

Nodal solutionStep = 1

Sub = 1

USUM (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0288E minus 03

MN

Freq = 0229855

(d)

Figure 16 Mode shape 1 (a) horizontal displacement (b) vertical displacement (c) lateral displacement and (d) total displacement

In soil mechanics the vertical effective stress 1205901015840 forexample is typically calculated by

1205901015840

= 120590119905

minus 119906 (4)

where 120590119905 and 119906 are total stress and pore pressure respectivelyFor a uniform layer with no pore pressure the total verticalstress at a depth119867may be calculated by

120590119905

= 120588119892119867 (5)

where 120588 represents the density of the layer and 119892 representsgravity In the conventional form of centrifugemodeling [26]it is typical that the same materials are used in the model andprototype therefore the densities are the same in model andprototype that is

120588lowast

= 1 (6)

Furthermore in conventional centrifugemodeling all lengthsare scaled by the same factor 119871lowast To produce the same stressin the model as in the prototype we thus require

120588lowast

119892lowast

119867lowast

= 1119892lowast

119871lowast

= 1 (7)

It may be rewritten as

119892lowast

=1

119871lowast

(8)

The above scaling law states that if lengths in the model arereduced by some factor 119899 then gravitational accelerationsmust be increased by the same factor 119899 in order to preserveequal stresses in model and prototype

Shock and Vibration 9

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(a)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(b)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(c)

1650

950

500 5200 500

1000

1000785 Water

Sand

Laterite reinforced

(d)

1650

950

1000

1000785

Laterite

Water

Sand

500 5200 500

(e)

Figure 17 Model introducing ((a) (b) (c) (d) and (e)) for small dam (cm) (119878 = 1100)

For dynamic problems where gravity and accelerationsare important all accelerations must scale as gravity is scaledthat is

119886lowast

= 119892lowast

=1

119871lowast

(9)

Since acceleration has units of 1198711198792 it is required that

119886lowast

=119871lowast

1198792

(10)

Hence it is required that

1

119871lowast

=119871lowast

1198792

or 119879lowast

= 119871lowast

(11)

Frequency has units of inverse of time and velocity has unitsof length per time so for dynamic problems we also obtain

119891lowast

=1

119871lowast

Vlowast =119871lowast

119879lowast

= 1 (12)

For model tests involving dynamics the conflict in time scalefactors may be resolved by scaling the permeability of the soil[26]

35 Free Vibration Analysis In dynamic assessment freevibration analysis is the base of study In fact the distributionof frequency in the different vibrationmode can be computedby the application of modal analysis based on finite-elementmethod (FEM) It is worth mentioning that this analysis isperfectly related to the mass and spring In case of the mass-spring-damper system the first assumption is negligibleabout damping effect Therefore there is not any externalforce on mass in this state The force applied to the massby the spring is proportional to the amount of the springthat is stretched ldquo119909rdquo (it can be assumed that spring isalready compressed due to the weight of the mass) Theproportionality constant (119896) is spring stiffness (see Figure 14)The unit measurement is force divided by distance (kgm)

10 Shock and Vibration

(a) (b)

(c) (d)

Figure 18 Small scale dam (a) Dam perspective with two LVDT (b) soil compaction with roller (c) dam section with index network and(d) dam with tank before vibration

The negative sign indicates that force is always opposingthe motion of the mass attached to it according to thefollowing equation

119865119904

= minus119896119909 (13)

The force generated by the mass is proportional to theacceleration of the mass as given by Newtonrsquos second law ofmotion

sum119865 = 119898119886 = 119898 = 1198981198892

119909

1198891199052

(14)

The sumof the forces on themass then generates this ordinarydifferential equation

119898 + 119896119909 = 0 (15)

Assuming that the initial vibration can be started by stretch-ing and releasing the spring with distance (119860) the solution tothe above equation that describes the motion of mass can beseen in the following equation

119909 (119905) = 119860 cos (2120587119891119899

119905) (16)

This solution shows that it will oscillate with simple harmonicmotion that has amplitude of (119860) and a frequency (119891

119899

) Thenumber (119891

119899

) is called the undamped natural frequency Forthe simple mass-spring system frequency is given by

119891119899

=1

2120587

radic119896

119898 (17)

However the relation between frequency and vibrationperiod is always reverse Consider

119879 =1

119891 (18)

In terms of the measurement unit the vibration periodand frequency were according to seconds and hertz It isworth noting that the dominant frequency is the minimumfrequency to produce maximum vibration period

4 Numerical Analysis

In terms of numerical analysismodal analysis was carried outby using ANSYS program in this study to compute dominantfrequency for small scale model regarding 3D analysis Thisprogram is one of the famous software programs with respectto finite-elementmethod (FEM) In particular this software isone of the universal programs with high level of the ability fordifferent analyses A strong ability to compute free vibrationanalysis is possible with modal analysis [27]

41 Elements and Meshing Process To select element basedon Help menu solid 8 nodes 183 (3D) were used for thispurpose Figure 15 shows the mapped mesh for numericalmodeling In this figure 23956 elements and 35457 nodes inmodels were used for free vibration analysis According tothis condition free vibration analysis to access frequency indifferent vibration modes was carried out as results can bediscussed in the next section

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

8 Shock and Vibration

Nodal solutionStep = 1

UX (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0271E minus 04

Sub = 1X

Y

Z

MN

MX

minus0271E

minus04

minus0210E

minus04

minus0150E

minus04

minus0902Eminus05

minus0301Eminus05

0301Eminus05

0902Eminus05

0150E

minus04

0210E

minus04

0271E

minus04

SMN = minus0271E minus 04

Freq = 0229855

(a)

Nodal solutionStep = 1

Sub = 1

UY (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0126E minus 03

X

Y

Z

MN

MX

minus0971E

minus04

minus0125E

minus03

minus0692E

minus04

minus0413Eminus04

minus0134Eminus04

0145Eminus04

0423E

minus04

0702E

minus04

0981E

minus04

0126E

minus03

SMN = minus0125E minus 03

Freq = 0229855

(b)

X

Y

Z MN

MX

0

0287E

minus04

0575E

minus04

0862Eminus04

0115Eminus03

0144Eminus03

0172Eminus03

0201E

minus03

0230E

minus03

0259E

minus03

Nodal solutionStep = 1

UZ (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0259E minus 03

Sub = 1

Freq = 0229855

(c)

X

Y

Z

MX0

0320E

minus04

0639E

minus04

0959Eminus04

0128Eminus03

0160Eminus03

0192Eminus03

0224E

minus03

0256E

minus03

0288E

minus03

Nodal solutionStep = 1

Sub = 1

USUM (Avg)RSYS = 0

DMX = 0288E minus 03

SMX = 0288E minus 03

MN

Freq = 0229855

(d)

Figure 16 Mode shape 1 (a) horizontal displacement (b) vertical displacement (c) lateral displacement and (d) total displacement

In soil mechanics the vertical effective stress 1205901015840 forexample is typically calculated by

1205901015840

= 120590119905

minus 119906 (4)

where 120590119905 and 119906 are total stress and pore pressure respectivelyFor a uniform layer with no pore pressure the total verticalstress at a depth119867may be calculated by

120590119905

= 120588119892119867 (5)

where 120588 represents the density of the layer and 119892 representsgravity In the conventional form of centrifugemodeling [26]it is typical that the same materials are used in the model andprototype therefore the densities are the same in model andprototype that is

120588lowast

= 1 (6)

Furthermore in conventional centrifugemodeling all lengthsare scaled by the same factor 119871lowast To produce the same stressin the model as in the prototype we thus require

120588lowast

119892lowast

119867lowast

= 1119892lowast

119871lowast

= 1 (7)

It may be rewritten as

119892lowast

=1

119871lowast

(8)

The above scaling law states that if lengths in the model arereduced by some factor 119899 then gravitational accelerationsmust be increased by the same factor 119899 in order to preserveequal stresses in model and prototype

Shock and Vibration 9

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(a)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(b)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(c)

1650

950

500 5200 500

1000

1000785 Water

Sand

Laterite reinforced

(d)

1650

950

1000

1000785

Laterite

Water

Sand

500 5200 500

(e)

Figure 17 Model introducing ((a) (b) (c) (d) and (e)) for small dam (cm) (119878 = 1100)

For dynamic problems where gravity and accelerationsare important all accelerations must scale as gravity is scaledthat is

119886lowast

= 119892lowast

=1

119871lowast

(9)

Since acceleration has units of 1198711198792 it is required that

119886lowast

=119871lowast

1198792

(10)

Hence it is required that

1

119871lowast

=119871lowast

1198792

or 119879lowast

= 119871lowast

(11)

Frequency has units of inverse of time and velocity has unitsof length per time so for dynamic problems we also obtain

119891lowast

=1

119871lowast

Vlowast =119871lowast

119879lowast

= 1 (12)

For model tests involving dynamics the conflict in time scalefactors may be resolved by scaling the permeability of the soil[26]

35 Free Vibration Analysis In dynamic assessment freevibration analysis is the base of study In fact the distributionof frequency in the different vibrationmode can be computedby the application of modal analysis based on finite-elementmethod (FEM) It is worth mentioning that this analysis isperfectly related to the mass and spring In case of the mass-spring-damper system the first assumption is negligibleabout damping effect Therefore there is not any externalforce on mass in this state The force applied to the massby the spring is proportional to the amount of the springthat is stretched ldquo119909rdquo (it can be assumed that spring isalready compressed due to the weight of the mass) Theproportionality constant (119896) is spring stiffness (see Figure 14)The unit measurement is force divided by distance (kgm)

10 Shock and Vibration

(a) (b)

(c) (d)

Figure 18 Small scale dam (a) Dam perspective with two LVDT (b) soil compaction with roller (c) dam section with index network and(d) dam with tank before vibration

The negative sign indicates that force is always opposingthe motion of the mass attached to it according to thefollowing equation

119865119904

= minus119896119909 (13)

The force generated by the mass is proportional to theacceleration of the mass as given by Newtonrsquos second law ofmotion

sum119865 = 119898119886 = 119898 = 1198981198892

119909

1198891199052

(14)

The sumof the forces on themass then generates this ordinarydifferential equation

119898 + 119896119909 = 0 (15)

Assuming that the initial vibration can be started by stretch-ing and releasing the spring with distance (119860) the solution tothe above equation that describes the motion of mass can beseen in the following equation

119909 (119905) = 119860 cos (2120587119891119899

119905) (16)

This solution shows that it will oscillate with simple harmonicmotion that has amplitude of (119860) and a frequency (119891

119899

) Thenumber (119891

119899

) is called the undamped natural frequency Forthe simple mass-spring system frequency is given by

119891119899

=1

2120587

radic119896

119898 (17)

However the relation between frequency and vibrationperiod is always reverse Consider

119879 =1

119891 (18)

In terms of the measurement unit the vibration periodand frequency were according to seconds and hertz It isworth noting that the dominant frequency is the minimumfrequency to produce maximum vibration period

4 Numerical Analysis

In terms of numerical analysismodal analysis was carried outby using ANSYS program in this study to compute dominantfrequency for small scale model regarding 3D analysis Thisprogram is one of the famous software programs with respectto finite-elementmethod (FEM) In particular this software isone of the universal programs with high level of the ability fordifferent analyses A strong ability to compute free vibrationanalysis is possible with modal analysis [27]

41 Elements and Meshing Process To select element basedon Help menu solid 8 nodes 183 (3D) were used for thispurpose Figure 15 shows the mapped mesh for numericalmodeling In this figure 23956 elements and 35457 nodes inmodels were used for free vibration analysis According tothis condition free vibration analysis to access frequency indifferent vibration modes was carried out as results can bediscussed in the next section

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

Shock and Vibration 9

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(a)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(b)

1650

950

500 5200 500

1000

1000785

Laterite

Water

Sand

(c)

1650

950

500 5200 500

1000

1000785 Water

Sand

Laterite reinforced

(d)

1650

950

1000

1000785

Laterite

Water

Sand

500 5200 500

(e)

Figure 17 Model introducing ((a) (b) (c) (d) and (e)) for small dam (cm) (119878 = 1100)

For dynamic problems where gravity and accelerationsare important all accelerations must scale as gravity is scaledthat is

119886lowast

= 119892lowast

=1

119871lowast

(9)

Since acceleration has units of 1198711198792 it is required that

119886lowast

=119871lowast

1198792

(10)

Hence it is required that

1

119871lowast

=119871lowast

1198792

or 119879lowast

= 119871lowast

(11)

Frequency has units of inverse of time and velocity has unitsof length per time so for dynamic problems we also obtain

119891lowast

=1

119871lowast

Vlowast =119871lowast

119879lowast

= 1 (12)

For model tests involving dynamics the conflict in time scalefactors may be resolved by scaling the permeability of the soil[26]

35 Free Vibration Analysis In dynamic assessment freevibration analysis is the base of study In fact the distributionof frequency in the different vibrationmode can be computedby the application of modal analysis based on finite-elementmethod (FEM) It is worth mentioning that this analysis isperfectly related to the mass and spring In case of the mass-spring-damper system the first assumption is negligibleabout damping effect Therefore there is not any externalforce on mass in this state The force applied to the massby the spring is proportional to the amount of the springthat is stretched ldquo119909rdquo (it can be assumed that spring isalready compressed due to the weight of the mass) Theproportionality constant (119896) is spring stiffness (see Figure 14)The unit measurement is force divided by distance (kgm)

10 Shock and Vibration

(a) (b)

(c) (d)

Figure 18 Small scale dam (a) Dam perspective with two LVDT (b) soil compaction with roller (c) dam section with index network and(d) dam with tank before vibration

The negative sign indicates that force is always opposingthe motion of the mass attached to it according to thefollowing equation

119865119904

= minus119896119909 (13)

The force generated by the mass is proportional to theacceleration of the mass as given by Newtonrsquos second law ofmotion

sum119865 = 119898119886 = 119898 = 1198981198892

119909

1198891199052

(14)

The sumof the forces on themass then generates this ordinarydifferential equation

119898 + 119896119909 = 0 (15)

Assuming that the initial vibration can be started by stretch-ing and releasing the spring with distance (119860) the solution tothe above equation that describes the motion of mass can beseen in the following equation

119909 (119905) = 119860 cos (2120587119891119899

119905) (16)

This solution shows that it will oscillate with simple harmonicmotion that has amplitude of (119860) and a frequency (119891

119899

) Thenumber (119891

119899

) is called the undamped natural frequency Forthe simple mass-spring system frequency is given by

119891119899

=1

2120587

radic119896

119898 (17)

However the relation between frequency and vibrationperiod is always reverse Consider

119879 =1

119891 (18)

In terms of the measurement unit the vibration periodand frequency were according to seconds and hertz It isworth noting that the dominant frequency is the minimumfrequency to produce maximum vibration period

4 Numerical Analysis

In terms of numerical analysismodal analysis was carried outby using ANSYS program in this study to compute dominantfrequency for small scale model regarding 3D analysis Thisprogram is one of the famous software programs with respectto finite-elementmethod (FEM) In particular this software isone of the universal programs with high level of the ability fordifferent analyses A strong ability to compute free vibrationanalysis is possible with modal analysis [27]

41 Elements and Meshing Process To select element basedon Help menu solid 8 nodes 183 (3D) were used for thispurpose Figure 15 shows the mapped mesh for numericalmodeling In this figure 23956 elements and 35457 nodes inmodels were used for free vibration analysis According tothis condition free vibration analysis to access frequency indifferent vibration modes was carried out as results can bediscussed in the next section

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

10 Shock and Vibration

(a) (b)

(c) (d)

Figure 18 Small scale dam (a) Dam perspective with two LVDT (b) soil compaction with roller (c) dam section with index network and(d) dam with tank before vibration

The negative sign indicates that force is always opposingthe motion of the mass attached to it according to thefollowing equation

119865119904

= minus119896119909 (13)

The force generated by the mass is proportional to theacceleration of the mass as given by Newtonrsquos second law ofmotion

sum119865 = 119898119886 = 119898 = 1198981198892

119909

1198891199052

(14)

The sumof the forces on themass then generates this ordinarydifferential equation

119898 + 119896119909 = 0 (15)

Assuming that the initial vibration can be started by stretch-ing and releasing the spring with distance (119860) the solution tothe above equation that describes the motion of mass can beseen in the following equation

119909 (119905) = 119860 cos (2120587119891119899

119905) (16)

This solution shows that it will oscillate with simple harmonicmotion that has amplitude of (119860) and a frequency (119891

119899

) Thenumber (119891

119899

) is called the undamped natural frequency Forthe simple mass-spring system frequency is given by

119891119899

=1

2120587

radic119896

119898 (17)

However the relation between frequency and vibrationperiod is always reverse Consider

119879 =1

119891 (18)

In terms of the measurement unit the vibration periodand frequency were according to seconds and hertz It isworth noting that the dominant frequency is the minimumfrequency to produce maximum vibration period

4 Numerical Analysis

In terms of numerical analysismodal analysis was carried outby using ANSYS program in this study to compute dominantfrequency for small scale model regarding 3D analysis Thisprogram is one of the famous software programs with respectto finite-elementmethod (FEM) In particular this software isone of the universal programs with high level of the ability fordifferent analyses A strong ability to compute free vibrationanalysis is possible with modal analysis [27]

41 Elements and Meshing Process To select element basedon Help menu solid 8 nodes 183 (3D) were used for thispurpose Figure 15 shows the mapped mesh for numericalmodeling In this figure 23956 elements and 35457 nodes inmodels were used for free vibration analysis According tothis condition free vibration analysis to access frequency indifferent vibration modes was carried out as results can bediscussed in the next section

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

Shock and Vibration 11

0 20 40 60 80 100 1200

minus01

minus02

minus03

minus04

minus05

minus06

62 minus029

90 minus048

Time (s)

Disp

lace

men

t (m

m)

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

03

025

02

015

01

005

0

Rela

tive

disp

lace

men

t (m

m)

96 024

Model A

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 2

15

1

05

0

minus05

minus1

minus15

84 15

104 minus064

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m) 25

2

15

1

05

0

minus05

minus1

104 213

Model B

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m)

01201008006004002

0minus002minus004

108 01

108 006

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

007

006

005

004

003

002

001

0

8 006

Model C

Time (s)0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

0201501005

0minus005minus01minus015minus02

90 017

26 minus017

0 20 40 60 80 100 120

Time (s)

Disp

lace

men

t (m

m) 015

01005

0

minus01minus015

minus005

minus02minus025

114 minus007116 minus022

Model DTime (s)

Disp

lace

men

t (m

m)

01

0

minus01

minus02

minus03

minus04

104 minus011

102 minus033

0 20 40 60 80 100 120

Up streamDown stream

Time (s)

0 10 20 30 40 50 60 70 80 90 100 110 120

Rela

tive

disp

lace

men

t (m

m)

03

025

02

015

01

0

005

86 025

Model E

Figure 19 Vertical displacement in both edges of the crest in models with relative displacement

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

12 Shock and Vibration

(a) (b) (c)

Figure 20 Damage in the first model (Model A)

(a) (b)

(c) (d)

Figure 21 Damage in the second model (Model B)

42 Free Vibration Analysis and Dominant Frequency Interms of modal analysis the free vibration analysis was cal-culated by ANSYS program Figure 16 shows displacement inthree directions of model and total displacement in the firstvibration mode because based on distribution of frequencyin the first mode to fifth mode it is important to note thatthe minimum frequency (022986Hz) was observed in thefirst vibration mode It means that the vibration period wasmaximum and critical in this mode

Distribution of frequency in different vibration modesindicated that this value was respectively obtained at026257Hz 028387Hz and 030135Hz in the vibration shapemodes 2 to 4

5 Results and Discussion Based on PhysicalSmall Scale Modeling

In order to find the best location of reinforcement in damfive small dams with different locations of reinforcementusing IDL material were vibrated by dominant frequency

(22986Hz) with respect to resonance condition Figure 17shows five small scale dams (Models (a) (b) (c) and (d))it is obvious that models have the same dimension In thisfigure the reinforced area was illustrated with a hatch areaFor example Model (d) indicated that all dam body wasreinforced For this purpose one steel box for modeling wasused This box made by five sheets of Plexiglas with 20mmthickness One of them was in the base of model The levelof reservoir was 75 of the dam height The scale parameterwas 1100 Itmeans thatmodel was one hundred times smallerthan prototypeThedamheightwas 227meter in reality but itwas made 227 cm in physical model In addition small scalemodeling was coupled by foundation Foundation materialwas dense sand with 75 relative density Sand propertieswere mentioned in soil mechanic test Figure 18 shows somedetails including dam perspective soil compaction networkindex and reservoir In this Figure two LVDT on the middleof model at the both edges of the crest were installed Inorder to achieve support one steel frame and one steel beamwere applied (see Figure 18(a)) However both LVDT wereconnected to data logger device by specific cables In terms

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

Shock and Vibration 13

(a) (b)

Figure 22 Damage in the third model (Model C)

of compaction soil for each layer the steel roller used wasselected by trial error methodWoodmolding with respect tocontrol slope via network index was used In order to avoidabsorption of soil water content both the described moldswere just soaked by water before use For tank purpose smallscale models were filled up by water with very slow rate

After vibration equal to two minutes for all modelsthe vertical displacement for both slopes such as upstreamand downstream were printed With respect to use of Excelprogram Figure 19 shows the distribution of vertical displace-ment in both edges in the middle of the crest and relativedisplacement in all models It was obvious that distributionof the vertical displacement indicated a same trend for bothmodels such as A and E In both models displacement valueswere negative during the vibration It means that both ofthem were in uplift condition In this figure also maximumandminimum peak of the relative displacement respectivelyoccurred in Models B and C with 213mm and 006mm It isalso worth noting that this value was at convergence positionfor Models A and E with 024mm and 025mm respectively

In terms of damage location in models Figure 20 showsthe damage in Model A which occurred at upstream anddownstream The level of damage was greater in upstream Itwas very sensible occurrence in case of hydrodynamic pres-sure along the vibration Also in this figure the maximumlongitudes cracks (see line C) were observed near to themiddle of dam at the crest For damage at downstream thetransverse cracks significantly occurred in dam toe

Figure 21 shows Model B that was damaged after vibra-tion It can be observed that dam was significantly damagedin some locations such as crest and surfaces Body cracks andfailure process dramatically occurred in both areas near toabutments Also in this figure one transverse crack in themiddle of the crest was seen (see Figure 20(c)) This damagewas significantly repeated at upstream in Model C but itwas placed in dam toe and it can be seen in Figure 22 Inaddition Model D was damaged in three places such as bothabutments and the middle of the upstream Figure 23 showsModel D that was damaged in toe Briefly all four modelswere damaged as discussed previously On the other handa successful way in order to remove damage was obtained inModel E as shown in Figure 24 Figure 24 shows that model

Figure 23 Damage in the fourth model (Model D)

was safe after vibration without any damage In this figurethe reinforced blanket layer using IDLmaterial was indicatedby red circles between dam and foundation In addition itwas very important to note that both surfaces were safe anddam was stable under severe seismic loading like resonancemotion In fact a good absorption of energy with respectto increase of damping was found by using IDL In case ofusing this technique displacement in both edges of the crestwith negative value indicated the uplift situation Moreoverrelative displacement was like the first model Thereforedam behavior before and after reinforcement was similar forboth distributions of displacement Nevertheless Model Ewas successful to remove damage with respect to high levelof damping in blanket layer In fact this model shows theexcellent performance in earth dams when the blanket layerwas expanded below tank

Finally blanket layer using isolator damper layer (IDL)below dam and tank is a good recommendation for earthdams in seismic zonewhen reinforced thickness is one-fourthof damheight As recommended optimization of thickness inthis method is the next study

6 Conclusion

In this study the earth dam performance under severeseismic motion such as resonance was evaluated by usingblanket layer (IDL) With respect to soil mechanic testthe optimum mixture for IDL was designed IDL powderwas made by using some materials Main material was alocal soil (laterite) with 90 and additives such as TDA

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

14 Shock and Vibration

(a) (b)

(c) (d)

Figure 24 Dam stabilization in the fifth model (Model E)

(tire derived aggregate with 7) and MS (microsilica) with3 were used This material was utilized to reinforce damin small scale physical modeling According to numericalanalysis the dominant frequency (02298Hz) in order tohave maximum effect for modeling vibration was computedBy using this frequency for physical modeling the damagelocation and distribution of vertical displacement at bothedges of the crest in the middle of small dams for five smallmodel with scale 1100 were discussed As results the bestperformance in order to remove damages was obviouslyobserved in Model E while other models were dramaticallydamaged in some locations such as upstream downstreamand crest In addition the thickness of blanket layer in thismodel was one-fourth of dam height Finally this model is anovel method to reinforce dam under strong earthquake likeresonance phenomena recommended for earth dam designin seismic zone

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

This study ismade possible by the support of the InternationalDoctorate Fellowship of Universiti Teknologi Malaysia andit is very much appreciated

References

[1] M Zeghal and A M Abdel-Ghaffar ldquoAnalysis of behavior ofearth dam using strong-motion earthquakes recordsrdquo Journalof Geotechnical Engineering vol 118 no 2 pp 266ndash277 1992

[2] V Gikas andM Sakellariou ldquoSettlement analysis of theMornosearth dam (Greece) evidence from numerical modeling andgeodetic monitoringrdquo Engineering Structures vol 30 no 11 pp3074ndash3081 2008

[3] R Verdugo N Sitar J D Frost et al ldquoSeismic performanceof earth structures during the February 2010 Maule Chileearthquake dams levees tailings dams and retaining wallsrdquoEarthquake Spectra vol 28 no 1 pp S75ndashS96 2012

[4] Y Parish and F N Abadi ldquoDynamic behaviour of earth damsfor variation of earth material stiffnessrdquo Proceedings of WorldAcademy of Science Engineering and Technology vol 50 pp606ndash611 2009

[5] T G Berhe X T Wang and W Wu ldquoNumerical investigationinto the arrangement of clay core on the seismic performanceof earth damsrdquo in Proceedings of the GeoShanghai InternationalConference on Soil Dynamics and Earthquake Engineering pp131ndash138 ASCE June 2010

[6] Z F Xia G L Ye J HWang B Ye and F Zhang ldquoFully couplednumerical analysis of repeated shake-consolidation process ofearth embankment on liquefiable foundationrdquo Soil Dynamicsand Earthquake Engineering vol 30 no 11 pp 1309ndash1318 2010

[7] X J Kong Y Zhou B Xu and D G Zou ldquoAnalysis on seismicfailure mechanism of Zipingpu dam and several reflections ofaseismic design for high rock-fill damrdquo in Proceedings of theEarth and Space pp 3177ndash3189 March 2010

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

Shock and Vibration 15

[8] A BayraktarM E Kartal and S Adanur ldquoThe effect of concreteslabrockfill interface behavior on the earthquake performanceof a CFR damrdquo International Journal of Non-Linear Mechanicsvol 46 no 1 pp 35ndash46 2011

[9] R P Piao A H Rippe B Myers and K W Lane ldquoEarthdam liquefaction and deformation analysis using numericalmodelingrdquo in Proceedings of the GeoCongress pp 1ndash6 March2006

[10] A W Elgamal ldquoThree-dimensional seismic analysis of la villitadamrdquo Journal of Geotechnical Engineering vol 118 no 12 pp1937ndash1958 1992

[11] B Gordan and B A Azlan ldquoEffect of material properties inCFRD tailing-embankment bridge during a strong earthquakerdquoCaspian Journal of Applied Sciences Research vol 2 no 11 pp61ndash72 2013

[12] A Papalou and J Bielak ldquoSeismic elastic response of Earthdams with canyon interactionrdquo Journal of Geotechnical andGeoenvironmental Engineering vol 127 no 5 pp 446ndash453 2001

[13] Y Yu L Xie and B Zhang ldquoStability of earth-rockfill damsinfluence of geometry on the three-dimensional effectrdquo Com-puters and Geotechnics vol 32 no 5 pp 326ndash339 2005

[14] L H Mejia and H B Seed ldquoComparison of 2-D and 3-D dynamic analyses of earth damsrdquo Journal of GeotechnicalEngineering vol 109 no 11 pp 1383ndash1398 1983

[15] J L Borges ldquoThree-dimensional analysis of embankmentson soft soils incorporating vertical drains by finite elementmethodrdquoComputers andGeotechnics vol 31 no 8 pp 665ndash6762004

[16] A Yildiz ldquoNumerical analyses of embankments on PVDimproved soft claysrdquo Advances in Engineering Software vol 40no 10 pp 1047ndash1055 2009

[17] B Le Hello and P Villard ldquoEmbankments reinforced by pilesand geosynthetics-Numerical and experimental studies dealingwith the transfer of load on the soil embankmentrdquo EngineeringGeology vol 106 no 1-2 pp 78ndash91 2009

[18] S W Abusharar J J Zheng B G Chen and J H Yin ldquoA sim-plified method for analysis of a piled embankment reinforcedwith geosyntheticsrdquo Geotextiles and Geomembranes vol 27 no1 pp 39ndash52 2009

[19] R Noorzad and M Omidvar ldquoSeismic displacement analysisof embankment dams with reinforced cohesive shellrdquo SoilDynamics and Earthquake Engineering vol 30 no 11 pp 1149ndash1157 2010

[20] T Matsumaru K Watanabe and J Isono ldquoApplication ofcement-mixed gravel reinforced by ground for soft groundimprovementrdquo in Proceedings of the 4th Asian Regional Confer-ence on Geosynthetics pp 380ndash385 Shanghai China June 2008

[21] Namdar and A A K Pelko ldquoSeismic evaluation of embank-ment shaking table test and finite element methodrdquo ThePacific Journal of Science and Technology vol 11 no 2 2010httpwwwakamaiuniversityusPJST

[22] L Wang G Zhang and J Zhang ldquoCentrifuge model tests ofgeotextile-reinforced soil embankments during an earthquakerdquoGeotextiles and Geomembranes vol 29 no 3 pp 222ndash232 2011

[23] H B Seed R T Wong I M Idriss and K Tokimatsu ldquoModuliand damping factors for dynamic analyses of cohesionless soilsrdquoJournal of Geotechnical Engineering vol 112 no 11 pp 1016ndash1032 1986

[24] B M Das Advanced Soil Mechanics CRC Press New York NYUSA 2013

[25] M J Griffin Handbook of Human Vibration Academic PressNew York NY USA 2012

[26] J Garnier C Gaudin S M Springman P J Culligan DJ Goodings and D Konig ldquoCatalogue of scaling laws andsimilitude questions in geotechnical centrifuge modellingrdquoInternational Journal of Physical Modelling in Geotechnics vol7 no 3 pp 1ndash23 2007

[27] A Fluent 120 Userrsquos Guide User Inputs for PorousMedia 2009

International Journal of

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RotatingMachinery

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Submit your manuscripts athttpwwwhindawicom

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of