Dynamic Analysis of Multistorey framed structure with roof tower
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Transcript of Dynamic Analysis of Multistorey framed structure with roof tower
DYNAMIC ANALYSIS
OF
MULTISTOREY FRAMED STRUCTURE
WITH ROOF TOWER
Guide :- Mr. PRAMOD TIWARI
PRESENTED BY: Amit Ranjan (2002309) Gupta Abhishek (2002964) Mohit Jain (2002355) Navdeep Kumar (2002357) Siddhant Raturi (2002403) Vipin Thapliyal (2002854)
INTRODUCTION
• Telecommunication structure designed for supporting parabolic antennas. e.g. microwave transmission for communication , radio and T.V signals.
• Self-supporting structures.
• Three-legged and Four-legged space trussed structures.
• Consideration of load. Seismic load. Wind load.
OBJECTIVES
Modeling of the tower.
Modeling of the building.
Study of the Response Spectra Method on the building with roof tower.
Study of the wind load on the building.
BUILDING USED
Building usedHeight of the building = 9.9 mNo. of storey 3
Tower 4 legged space tower height of the tower = 15m
1. Type of structure Multi-storey rigid jointed framed structure
2. Seismic zone Zone -IV
3. Number of stories Three ( G+2 )
4. Floor height 3.3 m
5. Infill wall250 mm thick including plaster in longitudinal and 150 mm in transverse direction
6. Imposed load 3 kN/m2
7. Materials Concrete ( M 25) and reinforcement (Fe 500)
8.Size of columns
460 mm x 340 mm
530 mm x 340 mm
450 mm x 340 mm
9. Size of beams450 mm x 230 mm
300 mm x 230 mm
10. Depth of slab 150 mm thick
11. Specific weight of RCC 24 kN/m3
12. Specific weight of infill 20 kN/m3
13. Type of soil Medium soil
14. Response spectra As per IS 1893 ( part 1): 2002
15. Time historyCompatible to IS 1893 ( part 1): 2002 spectra at medium soil for 5% damping.
Detailing of Building
1. Type of structure 4-Legged Steel Structure
2. Seismic zone Zone –IV
3. Height 15 m
4. Base Width 2.1 m
5. Poisson’s ratio 0.3
6. Young’s modulus of elasticity, Es2.11 x 105MPa
7. Materials Steel ISA 50X50X6
ISA 40X40X6
8. Axial Force 10KN in comp.
4KN in ten.
Detailing of Tower
GEOMETRY
GENERAL
PROPERTY SUPPORTS LOAD &
DEFINITION
CROSS SECTION
FIXED AND PINNED
DEFINITION
DYNAMIC LOAD
RESPONSE SPECTRA METHOD
LOAD CASE & DETAILS
ANALYSE
STEPS INVOLVED IN WORKING OF STAAD- PRO
RESPONSE SPECTRA
Response spectra is a very useful tool of earthquake engineering for analysing the performance of structure during earthquake. Response spectra is simply a plot of the peak or steady state response (disp., vel., ace.) Response spectra is measured using accelerograph.
RESPONSE SPECTRUM METHOD BY USING STAADPRO
The design lateral shear force at each floor in each mode is computed by STAAD in accordance with the IS: 1893 (Part 1) -2002
STAAD utilizes the following procedure to generate the lateral seismic loads.
[1] User provides the value for as factors for input spectrum. I* Z / 2 R
[2] Program calculates time periods for first six modes or as specified by the user.
[3] Program calculates Sa/g for each mode utilizing time period and damping for each mode.
[5] The program then calculates mode participation factor for different modes.
[6] The peak lateral seismic force at each floor in each mode is calculated.
[7] All response quantities for each mode are calculated.
[8] The peak response quantities are then combined as per method (CQC or SRSS or ABS ) as defined by the user to get the final results
[4] The program calculates design horizontal acceleration spectrum for different modes
RESPONSE SPECTRUM DATA SPECIFICATION
Mode shapeMode shape is the deformed shape of the building when shaken at natural period
Factors influencing Mode Shapes
(1)Effect of Flexural Stiffness of Structural Elements
(2) Effect of Axial Stiffness of Vertical Members
(3) Effect of Degree of Fixity at Member Ends
(4) Effect of Building Height
Wind :Wind is the term used for air in motion and is usually applied to the natural horizontal motion of the atmosphere.
Types of wind:1. Prevailing wind
2. Seasonal wind
3. Local wind
Design analysis of wind :
Design Wind Speed (Vz) :
Vz = Vb k1 k2 k3
Vz = design wind speed at any height z in m/s, k1 = probability factor (risk coefficient) k2 = terrain roughness and height factor k3 = topography factor
Design Wind Pressure (pz):
pz = 0.6 vz2
pz = wind pressure in N/m2 at height z, and Vz = design wind speed in m/s at height z.
1) 1.5(DL+LL) 2) 1.2(DL+LL) 3) 1.2(DL+LL+EQX)4) 1.2(DL+LL-EQX) 5) 1.2(DL+LL+EQZ) 6) 1.2(DL+LL-EQZ)7) 1.5DL8) 1.5(DL+EQX) 9) 1.5(DL+EQZ) 10) 1.5(DL-EQX) 11) 1.5(DL-EQZ) 12) 0.9DL+1.5EQX13) 0.9DL+1.5EQZ14) 0.9DL-1.5EQX15) 0.9DL-1.5EQZ
LOAD COMBINATIONS CONSIDERED IN THIS ANALYSIS ARE
PLAN
ELEVATION
PLAN AND ELEVATION OF STRUCTURE 1
PLAN
ELEVATION
PLAN AND ELEVATION OF STRUCTURE 2
PLAN
ELEVATION
PLAN AND ELEVATION OF STRUCTURE 3
0
12
Beam No.
Dis
pla
cem
ent
(mm
439 451 452 454 5580
0.5
1
1.5
Column No.
Dis
pla
cem
ent
(mm
)
CALCULATIONS FOR THE DISPLACEMENT OF BEAMS AND COLUMNS
FOR STRUCTURE 1
47648150951151253453591591791891992101234
Beam No.
Dis
pla
cem
en
t (m
m)
441 444 445 447 4500
0.5
1
1.5
2
Column No.
Dis
pla
cem
en
t (m
m)
FOR STRUCTURE 2
457
459
464
470
496
903
907
909
0
1
2
3
4
5
6
Beam No
Dis
pla
cem
en
t (m
m)
433 436 437 438 4390
0.5
1
1.5
Column No.
Dis
pla
cem
en
t (m
m)
FOR STRUCTURE 3
1. The displacement of structure 2 and 3 are more than that of structure 1 by comparing their graphical values which are generated with the help of software.
2. As the height of the building is 9.9 m and according to IS code the wind load is applied on the structures whose height is more than 10 m ,So there is no need of applying wind load.
RESULT AND CONCLUSION
Max. Displacement of beams and columns for structure with tower at 1st position
BEAM 486 488 489 493 494 498 499 537
MAX DISPLACEMENT 0.678 0.337 0.887 0.467 0.22 0.256 0.636 1.054
BEAM 540 917 918 919 920 921 922
MAX DISPLACEMENT 1.835 0.155 0.755 0.145 0.191 0.629 0.037
486
488
489
493
494
498
499
537
540
917
918
919
920
921
922
00.5
11.5
2
Beam No.
Dis
pla
cem
ent
(mm
)
439 451 452 454 5580
0.5
1
1.5
Column No.
Dis
pla
cem
ent
(mm
)
COLUMN 439 451 452 454 558
MAX DISPLACEMENT 1.224 1.143 0.815 0.861 0.602
REFERENCES
IS - 1893 – 2002 (part - 1)
IS - 875 (part - 3)
Bhosale N.Kumar P., Pandey A.D., (2012), Influence of Host Structure Characteristics on Response of Rooftop Telecommunication Towers, International Journal of Civil and Structural Engineering, 2(3), 2012.
Siddhesha H., (2010), Wind analysis of Microwave Towers, International Journal of Applied Engineering Research, Dindigul, 1(3), 574-584. Amiri G., Barkhordari M.A., Massah S. R., Vafaei M.R.,(2007), Earthquake Amplification Factors for Self-supporting 4-legged Telecommunication Towers, World Applied Sciences Journal, 6(2), 635-643.
McClure G., Georgi L., Assi R, (2004), Seismic considerations for telecommunication towers mounted on building rooftop, 13th World Conference on Earthquake Engineering, Vancouver, Canada, Paper No. 1988.
THANK
YOU