Indian Geotechnical Conference (IGC-2010)igs/ldh/files/igc 2015 pune... · Based on the soil...

50

th

IG

C

50th

INDIAN GEOTECHNICAL CONFERENCE

17th

– 19th

DECEMBER 2015, Pune, Maharashtra, India

Venue: College of Engineering (Estd. 1854), Pune, India

SITE CHARACTERIZATION AND BEARING CAPACITY ESTIMATION

FOR A SCHOOL BUILDING LOCATED ON HILLSLOPE R. Acharyya

1, A. Dey

2

ABSTRACT

Footings located on or near a slope (e.g. bridge piers on approach embankments, foundations of

transmission towers and buildings on the hill-slopes), the slope face acts as a finite boundary that leads to

an improper and limited development of the plastic region of failure as the foundation approaches the

limit state under the applied loading. Depending upon the location of the footing and steepness of the

slope, the above-mentioned phenomena might lead to substantial reduction in the bearing capacity of the

foundation. In addition, the presence of the unprotected face of the slope leads to noticeable outward

movement which in turn can lead to ominous settlement failure of the foundation. There exists a

significant lack of knowledge in estimating the bearing capacity predictions for footing on slopes.

North-eastern regions of India is experiencing massive outgrowth in the number of habitations leading to

widespread construction of residential and commercial buildings due to increasing urbanization. Majority

part of the terrain being covered by hills, the upcoming construction activities are either directly situated

on the hill slopes or on the artificially prepared terraces. For buildings, a common scenario which is

encountered with relation to foundations is that individual footings of the buildings are often located at

different levels and different depths of the embedment when placed on slope faces. In these conditions, it

is extremely necessary to understand the behavior of the soil under such multiple loading conditions,

since, based on the soil and loading characteristics, the originally stable slope faces might become

vulnerable to failure and may lead to a deformation based failure of the structure. It is utterly necessary to

identify the failure mechanism in such conditions, so that proper protective measures can be adopted if

the situation arises. Such failure mechanisms does not follow the conventional bearing capacity failure

theories developed for semi-infinite soil medium, and should be dealt with caution and intricacy.

This article reports about a detailed soil characterization conducted for a site at Teli, Arunachal Pradesh

which would be used to construct a school building resting on hill-slope. The foundation mostly

1Acharyya_Rana, Department of Civil Engineering, IIT Guwahati, Guwahati, India, [email protected]

2Dey_Arindam, Department of Civil Engineering, IIT Guwahati, Guwahati, India, [email protected]

mailto:[email protected]


R. Acharyya, A. Dey

comprises of isolated square footings located at different levels of embedment. The soil at the site is

observed to be mostly sandy with the presence of fine content. The soil also contains weathered rock

fragments composed of micaceous flakes. Disturbed soil from the site has been collected from three

different locations and an extensive laboratory investigation has been carried out to identify the important

physical and engineering properties of the same. Laboratory investigations namely specific gravity,

particle size distribution (dry sieve, wet sieve and hydrometer), Atterberg limits, free swell potential,

consolidation and consolidated drained triaxial tests have been carried out. Soils collected from different

locations, upon testing, indicated the stratum to be fairly homogeneous. Shear strength parameters

estimated from the tests have been used to evaluate the ultimate bearing capacity of the footings with

proper consideration of their locations on the slope face with theoretical and numerical analysis (PLAXIS

3D v2012) and comparison has been made of both analysis.

Keywords: Foundations on slopes, Soil characterization, Bearing Capacity, PLAXIS 3D

50

th

IG

C

50th


17th

– 19th



SITE CHARACTERIZATION AND BEARING CAPACITY ESTIMATION

FOR A SCHOOL BUILDING LOCATED ON HILLSLOPE

Acharyya, R., Research Scholar, Department of Civil Engineering, IIT Guwahati, [email protected].

Dey, A.*, Assistant Professor, Department of Civil Engineering, IIT Guwahati, [email protected].

ABSTRACT: Buildings in North-Eastern India are commonly built on shallow foundations without any proper

geotechnical characterization of the underlying soil. This paper reports about a thorough geotechnical investigation

attempted for a site at Teli, Arunachal Pradesh, where a monastery school building is to be built on the slope face

of a hill. Soil samples have been collected from the site and several laboratory investigations have been carried out.

Based on the soil properties, both theoretical analysis and numerical simulations have been carried out to estimate

the bearing capacity and explore the deformation mechanisms of a single isolated footing.

INTRODUCTION

The ultimate bearing capacity of shallow

foundation placed near or on the slope has been a

matter of concern for the foundation engineers for

a long time. Foundations are sometimes located on

the faces of the slopes or near the edges of slopes.

Examples of such practice are buildings or roads

constructed in hilly regions, electric transmission

towers built on mountain slopes, and foundations

for bridge abutments resting on granular fill slopes.

The bearing capacity of a foundation constructed

near the edge of a slope assumes its importance in

view of the fact that performance of the structure

and the bearing capacity primarily depends on the

stability of the slope. Alike to the foundations

resting on horizontal ground surface, a shallow

footing in a slope can also be subjected to a variety

of loading (axial, inclined, eccentric, coupled

moments or their combinations). However, in

contrary to the former, the response of footings on

slopes becomes more critical due to a noticeable

reduction in ultimate bearing capacity [1, 2, 3].

This is primarily attributed to the incomplete

development of the passive zone near the slope

face where there is not enough lateral restraint on

the soil to resist it outward lateral movement

resulting in substantial reduction in the bearing

capacity and ominous outward deformation of the

foundation. Although the issue is of major

significance, experimental studies related to the

behaviour of footings on slopes are rather limited.

Majority of the experimental investigations [2, 3, 4,

5, 6) have been conducted in the laboratory on dry

cohesionless sandy soil with the objective of

estimating the ultimate bearing capacity and the

associated bearing capacity factor (Nγq) while

studying the effect of various influencing

parameters (e.g. setback distance, width of the

footing, relative density of slope material,

steepness of the slope and type of loading on the

footing) on the bearing capacity reduction factor.

Except for very few tests conducted on square

footings resting on the crest of the slope, [5], all the

above-mentioned experimental investigations have

been conducted on strip footings. The results of the

investigations conducted on a skirted strip footing

resting on the crest of sandy slope have been

reported in [7]. Apart from laboratory

investigations, meagre numbers of field

measurement related to the behaviour of anchored

inclined footings on a natural slope have been

reported in [8].

If the spread of habitation in the North-Eastern

(NE) regions of India are glimpsed, one can easily

recognize the locations to be primarily on

unreinforced hill-slopes or terraces of the same

(Photograph 1). With the passage of time, growing

inhabitation and changing trends of the building

structures (from light-weight Assam-type housing

to multi-storied concrete structures) is gradually

appending to changing deformation and instability



R. Acharyya, A. Dey

of the slopes because of inadequate design of the

foundation resting on or near the slope.

Photograph 1 Residential habitation on the hill-

slopes of Bomdila, Arunachal Pradesh

The present investigation has been carried out with

disturbed soil samples collected from the site at

Teli, Arunachal Pradesh. The soil has been

collected from three different locations and an

extensive laboratory investigation has been carried

out to identify the important physical and

engineering properties of the same. Strength and

stiffness parameters estimated from the tests have

been used to evaluate the bearing capacity of the

footings with proper consideration of their

locations on the slope face. Numerical FE

modelling has been done with PLAXIS 3D v2012

to validate the bearing capacity that has been

obtained from the theoretical analysis and make an

introspective study of the involved deformation

mechanisms.

EXPERIMENTAL INVESTIGATION AND

SOIL CHARACTERISATION

Detailed laboratory experiments have been

conducted to characterise the soils collected from

two different locations at the project site (L1 and

L2), as exhibited in Photograph 2. Two soil

samples (S1 and S2), at depths of 1 m and 1.5 m

respectively from the ground surface, have been

collected from Location 1. The third soil sample

(S3) was collected from a depth of 1 m below the

ground level at Location 2. Various laboratory tests

have been conducted on the soils samples for the

determination of specific gravity, Atterberg limits

(Liquid limit, Plastic limit and Shrinkage limit),

free swell index, particle size distribution,

compaction characteristics, shear strength

characteristics and consolidation characteristics. A

briefing of the conducted experiments is provided

in the subsequent sections.

Photograph 2 Shallow foundations being laid for a

school building on slope at Teli, Arunachal

Pradesh

Specific Gravity

As per [9]¸ specific gravity of each sample was

determined using a specific gravity bottle by taking

10 gm of oven dried soil sample passing through

4.75 mm sieve.

Atterberg Limits

Liquid Limit and Plastic Limit

As per [10]¸ liquid limit (LL) determination was

conducted with the aid of Casagrande apparatus by

taking 120 gm of oven dried soil sample passing

through 425 µm sieve.

As per [10]¸ plastic limit (PL) was determined for a

soil sample by making thread of 3 mm diameter

with the oven dried soil sample of 8 gm mixed with

appropriate water content.

Shrinkage Limit

As per [11], shrinkage limit of 30 gm soil sample

was evaluated using the mercury displacement

method.

L1

L2

50

th

IG

C

50th


17th

– 19th



Free Swell Index

As per [12], the free swell index was obtained for

oven dried soil sample passing through 425µm

sieve. Soil sample of 10 gm was poured in each of

the two graduated glass cylinders of 100 ml

capacity. One cylinder was then filled with

kerosene oil and the other with distilled water up to

the 100 ml mark. The volume of soil was checked

after 24 hours to identify the amount of expansion

in volume.

Sieve Analysis

Since the collected soil sample possessed a visually

significant fine content, as per [13], wet sieve

analysis has been done for each soil sample. Oven

dried soil sample of 500 gm was taken and washed

over 75 µm sieve under flowing tap water until the

clean water was observed to be passing from the

sieve. The soil retained on 75µm sieve was oven

dried and sieved through the set of IS sieves 4.75

mm, 2.80 mm, 2 mm, 1 mm, 600 µm, 425 µm, 300

µm, 150 µm, and 75 µm. based on the obtained

particle size distribution (PSD), the coefficient of

curvature (Cc) and coefficient of uniformity (Cu)

were calculated.

Hydrometer Analysis

As per [13], hydrometer analysis was performed

with 50 gm oven dried soil sample passing through

75µm sieve. Sodium hexametaphosphate solution

was used as a dispersing agent and soil was

thoroughly mixed. Hydrometer and thermometer

were used as the specified time to take the readings

for the corresponding mix density and the

temperature of the suspension. The particle size

distribution of the finer fraction has been

estimated.

Proctor Compaction

As per [14], standard proctor compaction test was

carried out using 2.5 kg oven dried soil sample

passing through 4.75 mm sieve. Proctor mould was

filled with soil mixed with desired water content in

three layers and each layer was compacted by 25

blows of a 2.6 kg rammer falling from 310 mm

height. The optimum moisture content (OMC) and

maximum dry density (MDD) is determined from

the test.

Unconfined Compressive Strength

As per [15], unconfined compressive strength

(UCS) of soil was determined using oven dried soil

sample passing through 4.75 mm sieve. Cylindrical

soil sample of 38 mm diameter and 76 mm height

was formed with optimum moisture content and

maximum dry density of soil obtained from Proctor

compaction and was subjected to compression in

the absence of any applied confining pressure.

Triaxial Shear Test

As per [16, 17], unconsolidated undrained (UU),

consolidated undrained (CU), and consolidated

drained (CD) triaxial shear tests were performed on

cylindrical soil (passing through 4.75 mm sieve)

samples of 38 mm diameter and 76 mm height

formed with optimum moisture content and

maximum dry density. Although the codes suggest

saturating the soil samples, in the present study the

tests were performed with soil sample formed with

optimum moisture content and maximum dry

density to get shear strength parameters of soil in

actual field condition.

Oedometer Test

As per [18], oedometer Test was performed to

evaluate the consolidation characteristics of oven

dried soil sample passing through 4.75 mm sieve.

The sample of 60 mm diameter and 2 mm height

was prepared in its OMC-MDD condition. The test

was continued using a loading sequence of

successively increasing applied stresses (20, 50,

100, 200, 400, 800 kN/m2) on the soil specimen.

The settlement under each loading stage was

observed in a specified time sequence (0, 1/4, ½, 1,

2, 4, 8, 15, 30, 60 min and 2, 4, 8, 24 hr).

Results and Discussions

The engineering properties and shear strength

properties of the soil samples tested in the

laboratory have been tabulated in Table 1 and

Table 2, respectively. It was found during the

R. Acharyya, A. Dey

evaluation of Atterberg limits that formation of 3

mm thread for PL determination was difficult, as

the micaceous elements present in all the samples

resulted in premature crumbling of the specimens

without allowing the formation of threads.

Table 1 Engineering properties of soil samples Properties Soil type

S1 & S2 S3

Specific gravity 2.71 2.61

Particle size distribution

Sand (%) 60 44

Silt (%) 28 42

Clay (%) 12 14

Coefficient of curvature 0.76 0.85

Coefficient of uniformity 3.67 4.70

Atterberg Limits

LL (%) 44.9 44.9

PL (%) - -

SL (%) 23.80 23.80

Free swell index (%) 10 10

Compaction characteristics

OMC (%) 17.7 17.4

MDD (gm/cc) 1.87 1.77

Consolidation characteristics

Compression index Cc 0.093 0.1096

Swelling index Cs 0.039 0.0374

Preconsolidation stress 90 100.5

Table 2 Shear strength properties of soil samples

Properties Value

UCS (kPa) 178.24

Cohesion c (kPa)

UU 12

CU 0

CD 7.8 Angle of internal friction φ (degree)

UU 43

CU 44 CD 45

Figures 1 and 2 reveal the particle size distribution

of the specimens collected. Soil samples S1 and S2

exhibit nearly identical characteristics, ad hence,

only one curve is shown for both the samples. The

curves show that the soils were nearly same in

composition. It is observed from the coefficients of

uniformity and curvature, as well as from Figure 1,

that the soil samples are nearly well-graded.

Presence of fines as observed from the particle size

distribution of the coarser and finer fractions

indicate that it is a c-φ soil.

Figure 1 Particle size distribution of coarser

fraction obtained from wet sieve analysis

Figure 2 Particle size distribution of finer fraction

obtained from hydrometer analysis

Figure 3 exhibits the compaction characteristics of

the soil samples which is found to be nearly

similar, the magnitude of which are mentioned in

Table 1. It can be observed that although the

compaction curves of the samples showed a

deviation in their dry of optimum state, the OMC-

MDD states obtained are nearly the same. The

deviation can be attributed to the discrepancy in

preparation of the sample using low water content.

Figures 4-8 depict the consolidation characteristics

of the soil samples. Figure 4 depicts a typical

e-log p curve obtained from the consolidation test.

The plot have been used to estimate the

compression index (Cc), swelling index (Cs), and

50

th

IG

C

50th


17th

– 19th



the preconsolidation pressure (pc) of the soil

samples. The virgin- or the field-compression

curve has also been identified from the same.

These parameters can primarily be used to model

the constitutive behaviour of the soil in any

numerical analysis, as well as for the simplistic and

crude estimation of settlements which might take

place at the site. The magnitudes of the above-

mentioned parameters are mentioned in Table 1,

which shows that the soil samples do not differ

considerably from each other.

Figure 3 Compaction characteristics from

Standard Proctor compaction test

Figure 4 Typical e-log p curve obtained from

oedometer test for soil sample S1

The variation of coefficient of permeability (k)

with stress has been presented in Figure 5 and it is

revealed that the coefficient of permeability

becomes asymptotic beyond an applied stress of

500 kPa. Figure 6 exhibits that the coefficient of

consolidation (Cv) varies with applied stress. Cv is

observed to increase up to an applied stress of 200

kPa, beyond which it decreases and tends towards

an asymptote. Figure 7 and 8 depicts that the

coefficient of compressibility (av) and coefficient

of the volume compressibility (mv) decreases with

the increase in applied stress which is primarily

attributed to the decrease in void ratio with

progressive consolidation of the sample.

Figure 5 Variation of k with applied stress

Figure 6 Variation of Cv with applied stress

Figure 9 shows the comparative p-q plot obtained

from the stress-strain characteristics of various

triaxial tests (UU, CU, CD), which have been used

to estimate the shear strength characteristics of the

soil (as mentioned in Table 2). Based on the

obtained compaction characteristics, the triaxial

tests were carried out by preparing soil specimens

R. Acharyya, A. Dey

with MDD and its corresponding OMC. It is

observed that all the three tests result in nearly

identical shear strength parameters.

Figure 7 Variation of av with applied stress

Figure 8 Coefficient of mv with applied stress

Figure 9 Comparative p-q plot for triaxial tests

The above section presents a first-ever complete

geotechnical characterization of the soil at project

site at Teli, Tawang, Arunachal Pradesh. Based on

the above findings, it can be stated that for the site

in consideration, the engineering characteristics of

the soil samples collected from different locations

does not vary by a significant amount. Hence, the

soil at the site can be considered to be nearly

homogeneous. The estimated magnitudes of the

parameters will be further used to define the soil

properties for numerical modelling as well as the

estimation of the bearing capacity by analytical

methods.

BEARING CAPACITY ESTIMATION BY

ANALYTICAL METHOD

Meyerhof’s bearing capacity equation and chart for

bearing capacity factors [19, 20] have been used

for evaluating the ultimate bearing capacity of

shallow square footing of 2 m width resting on flat

ground surface, slope crest and sloping ground

surface. Ultimate bearing capacity (qu) of a 2 m

wide square footing has been calculated using the

shear strength parameters obtained from CD test.

The bearing capacity equations for square footing

resting on horizontal ground and slope are

respectively given as:

0.4u c f qq cN D N BN (1)

0.4u cq qq cN BN (2)

where, Df is the footing embedment depth, B is the

width of footing, γ is the unit weight of soil (MDD

as obtained from Proctor test). Nc, Nq, and Nγ are

Meyerhof’s bearing capacity factor for footing

resting on horizontal ground surface, while Ncq and

Nγq are Meyerhof’s resultant bearing capacity

factors for footing resting on a slope. qu has been

estimated for footings at various locations which

are elaborated in the following section and the

estimated magnitudes are provided in Table 6.

NUMERICAL FE MODELLING

Brief Overview of PLAXIS 3D

PLAXIS 3D is a finite element package intended

for three-dimensional analysis of deformation,

stability and ground water flow in geotechnical

50

th

IG

C

50th


17th

– 19th



engineering. Geotechnical applications require

advanced constitutive models for simulations of

non-linear, time-dependent and anisotropic

behaviour of soil or rock. Moreover, since the soil

is multi-phase material, special procedures are

required to deal with hydrostatic and non-

hydrostatic pore pressure in soil. Many

geotechnical projects involve the modelling of

structures and the interaction between structures

and the soil. PLAXIS 3D is equipped with features

to deal with various aspects of complex

geotechnical structures.

Model Details and Description

Geometry

In the present study, two types of model geometry

have been used. One of the model geometry (G1)

has been formed by considering footing on

horizontal ground surface or footing below

horizontal ground surface (Figure 10). The other

model geometry (G2) has been formed by

considering footing on slope crest or footing on

slope face (Figure 11). The geometry details are

tabulated in Table 3. The dimensions of the models

have been chosen in such a way that the ‘0.1q’

stress contour (q is the stress applied by the

footing’ should not be intersected by the side and

bottom edges of the model.

Table 3 Model geometry details Model

description

Breadth

(m)

Length

(m)

Height

(m)

Slope

angle (β°)

G1 14 14 12 0

G2 14 31.79 12 34

In the present study, horizontal fixity was given to

the four vertical edges of the model. In the bottom

edge of the model, both vertical and horizontal

fixity were applied as the bottom is assumed to be

non-yielding. This boundary condition is referred

as the “standard fixity” in the software (Typically

shown for model G2 in Figure 12).

Meshing and Convergence

To perform finite element calculation, the model

was discretized into smaller finite number of

tetrahedral elements. The basic soil elements of 3D

finite element mesh are the 10-noded tetrahedral

elements. PLAXIS 3D program allows for a fully

automatic generation of finite element meshes. In

PLAXIS 3D, five types meshing is available like

very coarse, coarse, medium, fine, and very fine.

Typical meshing for model G2 has been shown in

Figure 13.

Figure 10 Footing on horizontal ground (G1)

Figure 11 Footing on sloping ground (G2)

The mesh should be sufficiently fine to obtain

accurate numerical results. On the other hand, very

fine meshes should be avoided since it will take

excessive time for calculations. A convergence

study has been done with typical footing location

for five different meshing (represented by their

average element length) to understand the effect of

mesh refinement on the obtained results. Figure 14

exhibits that beyond a medium mesh, the obtained

R. Acharyya, A. Dey

results are nearly identical in all practical

considerations. Hence, all the further studies are

conducted considering a medium mesh having a

non-dimensional average element size (0.036).

Figure 12 Typical boundary conditions for G2

Figure 13 Typical meshing adopted in PLAXIS

3D

Material Model

The soil is modelled by the linear elastic perfectly-

plastic Mohr-Coulomb (M-C) model which

involves five input parameters, i.e. elastic

parameters (stiffness E and Poisson’s ratio ν) and

strength parameter (φ and c for soil plasticity and ψ

as an angle of dilatancy). The soil properties for the

M-C model have been tabulated in Table 4.

Table 4 Soil properties E (kPa) ν c (kPa) φ (°) ψ (°) γ (kN/m

3)

40104

0.3

7.67

45

0

18.7

Table 5 Footing properties Modulus of

elasticity

(E) (kPa)

Poisson's

ratio

(µ)

Unit weight

(γ) (kN/m3)

Thickness

(d) (m)

210 x 106

0.265

78

0.02

In the present study, the footing is represented by a

plate element modelled as a linear isotropic

material. The properties of pate have been

tabulated in Table 5.

Figure 14 Convergence study for a typical FE

model

Calculation Phases

The complete numerical analysis has been done in

three stages for all the models. In the first stage,

only the soil model was activated for generation of

in-situ stresses. In the second stage, the plate was

activated to represent the presence of constructed

footing. The column load was activated in the third

and final stage to assess the stress-deformation

conditions in the medium.

Footing Locations

Figure 15 Footing locations adopted for analysis

Figure 15 depicts the location of footings for which

the numerical analysis has been carried out to

estimate the bearing capacity in a numerical

framework. Different conditions have been

considered to represent surface and embedded

footings on horizontal (P1 and P2) and sloping (P3

and P4) ground, and a footing resting on the slope

face (P5) as well.

50

th

IG

C

50th


17th

– 19th



MODELLING OUTCOMES

Ultimate Bearing Capacity from FE Modelling

Footings at any of the locations (as mentioned in

Figure 15) were subjected to a high applied stress

so that the system undergoes failure and the failure

load can be ascertained. The load at failure is

obtained as a fraction (given as ΣMstage in PLAXIS

3D) of the total applied load. At failure, the

maximum stress generated beneath the footing is

considered as the ultimate bearing stress.

Table 6 Comparison of ultimate bearing capacity

Footing

Location

Ultimate bearing capacity (qu) (MPa)

Analytical Numerical

P1 4.91 14

P2 9.12 26.9

P3 2.28 8.97

P4 4.69 15.9

P5 1.39 6.61

Figure 16 Representative pressure bulbs for

footing at various locations

Table 6 provides a comparison of the ultimate

bearing capacity obtained from analytical and

numerical methods for footings at various

locations. It is observed that the ultimate bearing

capacities obtained from numerical analysis are

consistently higher in comparison to the analytical

estimates. This is primarily attributed to the

inefficacy of the theoretical method to take into

account the effect of 3-D confinement generated

for footings under practical considerations. Figure

16 shows representative pressure bulb diagram

revealing the stress distribution beneath the

footings P3, P4 and P5. Pressure bulbs are

manifestation of isobars which join points of equal

pressure generated due to the loaded footing. The

shape of isobars, obtained by the application of

Boussinesq’s principle, is found to be smooth.

However, Figure 16 reveals that the stress

distribution beneath the footing resting in a c-φ soil

will be rather distorted, which is attributed due to

the inherent non-linearity in the medium.

CONCLUSION

This article reports about a detailed soil

characterization conducted for a site at Teli,

Arunachal Pradesh which would be used to

construct a school building resting on hill-slope.

Theoretical and the FE analyses have been

conducted to estimate the bearing capacity of

footings resting on horizontal ground surface and

on or near slopes. Based on the present study, the

following main conclusions are drawn:

The soil samples collected from locations

L1 and L2 are found to possess nearly

identical characteristics, and hence, the site

can be attributed to be nearly

homogeneous.

Convergence study conducted for the FE

analysis revealed that a medium meshing is

sufficient for the present problem to obtain

accurate results.

Since the extent of the site is large in

comparison to the footing dimensions, the

model dimensions for the numerical study

are determined based on the assessment that

the pressure contour (of 10 percent applied

stress) was not intersected by the sides of

the model.

It has been seen that the ultimate bearing

capacity of the foundation obtained from

the numerical technique is consistently

higher than that obtained from analytical

estimates, which is attributed to the inherent

assumptions behind the theoretical

calculations which does not take into

account the 3-D confinement effect at the

site.

R. Acharyya, A. Dey

REFERENCES

1. Meyerhof, G.G. (1957), The ultimate

bearing capacity of foundation on slopes,

Proceedings of 4th

international conference

on soil mechanics and foundation

engineering, I, 384-386.

2. Shields, D., Chandler, N. and Garnier, J.

(1990), Bearing capacity of foundation in

slopes, Journal of Geotechnical

Engineering, 116(3), 528-537.

3. Bauer, G.E., Shields, D.H., Scott, J.D. and

Gruspier, J.E. (1981), Bearing capacity of

footing in granular slope, Proceedings of

the 11th

International Conference on Soil

Mechanics and Foundation Engineering,

Balkema, Rotterdam, The Netherlands, 2,

33-36.

4. Kumar, S.V.A. and Ilamparuthi, K. (2009),

Response of footing on sand slopes,

Conference Proceeding of the Indian

Geotechnical Conference, 622–626.

5. Castelli, F. and Lentini, V. (2012),

Evaluation of the bearing capacity of

footings on slopes, International Journal of

Physical Modelling in Geotechnics, 129(3),

112-118.

6. Keskin, M. S. and Laman, M. (2012),

Model Studies of Bearing Capacity of Strip

Footing on Sand Slope, KSCE Journal of

Civil Engineering, 17(4), 699-711.

7. Azzam, W.R and Farouk, A. (2010),

Experimental and Numerical Studies of

Sand Slopes Loaded with Skirted Strip

Footing, Electronic Journal of

Geotechnical Engineering, 15, 795-812.

8. Clark, J. I. and Mckeown, S. (1988), Field

measurements of the behaviour of inclined

footings on a natural slope, Canadian

Geotechnical Journal, 25, 662–674.

9. IS 2720 (Part III/Section I):1980

(Reaffirmed 2002) Method of test for soils:

Determination of specific gravity: Fine

grained soils.

10. IS 2720 (Part V):1980 (Reaffirmed 2006)

Method of test for soils: Determination of

liquid and plastic limit.

11. IS 2720 (Part VI):1972 (Reaffirmed 2001)


shrinkage factor.

12. IS 2720 (Part XL):1977 (Reaffirmed 2002)


free swell index of soil.

13. IS 2720 (Part IV):1985 (Reaffirmed 2006)

Method of test for soils: Grain size

analysis.

14. IS 2720 (Part VII):1980 (Reaffirmed 2002)


water content-dry density relation using

light compaction.

15. IS 2720 (Part X):1991 (Reaffirmed 2006)


unconfined compressive strength

16. IS 2720 (Part XI):1993 (Reaffirmed 2002)


shear strength parameters of a specimen

tested in unconsolidated undrained triaxial

compression without the measurement of

pore water pressure.

17. IS 2720 (Part XII):1981 (Reaffirmed 2002)


shear strength parameters of a specimen

tested in consolidated undrained triaxial

compression with the measurement of pore

water pressure.

18. IS 2720 (Part XV):1965 (Reaffirmed 2002)


consolidation properties.

19. Das, B. M. (2009), Shallow Foundations,

Taylor and Francis.

20. Arora, K. R. (2011), Soil Mechanics and

Foundation Engineering, Standard

Publishers and Distributors.

Indian Geotechnical Conference (IGC-2010)igs/ldh/files/igc 2015 pune... · Based on the soil...

Documents

Transcript of Indian Geotechnical Conference (IGC-2010)igs/ldh/files/igc 2015 pune... · Based on the soil...