COMPARATIVE STUDY ON HIGH-RISE BUILDING DUE TO EFFECT … · High-Rise buildings as defined by...

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International Journal of Advanced Research in Engineering and Technology (IJARET) Volume 9, Issue 4, July - August 2018, pp. 259–271, Article ID: IJARET_09_04_027

Available online at http://www.iaeme.com/IJARET/issues.asp?JType=IJARET&VType=9&IType=4

ISSN Print: 0976-6480 and ISSN Online: 0976-6499

© IAEME Publication

COMPARATIVE STUDY ON HIGH-RISE

BUILDING DUE TO EFFECT OF LATERAL

FORCES USING ETABS

Amanullah Qureshi

Department of Civil Engineering,

Final Year Student, Ghousia college of Engineering, Ramanagaram,

VTU, Belgaum, Karnataka, India

Ummer Farooq Pasha


Assistant Professor, Ghousia college of Engineering, Ramanagaram,


N S Kumar


Professor and Director (R&D-Civil Engineering),

Ghousia college of Engineering, Ramanagaram


ABSTRACT

Conventional slab and Post Tensioned slab structures of G+15 floors for an

assumed architectural plan has been analyzed and compared by applying lateral

forces i.e., seismic zone II and V and wind zone I and V respectively. The analysis has

done using ETABS software for both the structures and compared the responses by

obtaining results of base shear, maximum storey displacement, storey drift and storey

shear. The limiting values for drift and displacement has been validated with Indian

code provision for earthquake consideration and British code for wind consideration.

The static and response spectrum analysis has done for seismic analysis to compare

both method’s results.

Key words: AutoCAD, ETABS, High-Rise building, Post Tensioned slab, Prestressed

Concrete, Seismic zones, Wind zones.

Cite this Article: Amanullah Qureshi, Ummer Farooq Pasha and N S Kumar,

Comparative Study on High-Rise Building Due to Effect of Lateral Forces Using

ETABS. International Journal of Advanced Research in Engineering and Technology,

9(4), 2018, pp 259–271.

http://www.iaeme.com/IJARET/issues.asp?JType=IJARET&VType=9&IType=4

Comparative Study on High-Rise Building Due to Effect of Lateral Forces Using ETABS


1. INTRODUCTION

High-Rise buildings as defined by Council on Tall Buildings and Urban Habitat Buildings

height more than 50m is titled as Tall Building. Buildings height more than 100m is called as

skyscraper. Buildings height of 300m or higher is called as Super tall. Buildings height of

600m or higher is named as Mega-tall. Evaluation of Height of tall buildings, Height to

Architectural Top Height to tip Highest Occupied floor. Many high-rise buildings are

constructed worldwide, remarkably in Asian countries, such as China, Korea, Japan, and

Malaysia. Based on data published in the 1980s, about 49% of the world‟s high-rise buildings

were located in North America. The distribution of high rise buildings has changed

thoroughly with Asia now having the largest contribution with 32%, and North America is at

24%. Pre-stressing is generally a way to overcome concrete weakness in tension. Generally,

the concrete undergoes compression on top flange and tension at bottom flange. In pre-

stressing the tendons are stretched along the axis and cement is poured, later when the tendons

are released the compression is generated at the bottom which tries to counter-balance the

compression due to loading at the top part of the member. The upward force along the length

of the concrete member counteracts the service loads applied to the member. There are two

methods of prestressing are widely used they are: Pre-tensioning and Post-tensioning.

1.1. Objectives: The various objectives of my project work are discussed below

To study the behaviour of tall structures with conventional slab and post tensioned slab

due to effect of lateral forces.

To model and analyses a structure with conventional slab and post tensioned slab using

ETABS software.

To model and analyses the buildings with conventional and post tensioned slab by

considering two different seismic zones of India i.e., Zone II, and V as per IS 1893(Part

1):2002

To model and analyses the structures in two wind zones of India i.e., Zone I, and V as per

IS 875(Part-3)-1987.

To compare the results and to check the safety of the structure against allowable limits

prescribed for base shear, maximum displacements, storey drifts and shear in codes of

practice and other references in literature on effects of earthquake and wind loads on

buildings.

However, in this study the business building like shopping mall is considered with g+15

floors having plinth area of 980.085 m2 and storey height of 5m at ground floor and 3m from

1st floor to 15

th floor has been considered. the shopping mall consist of various division and it

is shown in AutoCAD plan under section 2.1.7 and Fig.2.3. the seismic zones considered in

this study along with their respective locations are shown in Table-1.1 and for the wind

analysis the different wind zones and their wind speed in m/s considered according to their

specific are in Table-1.2

Table 1.1

Location State Seismic Zones Seismic Activity

Bangalore Karnataka II Low

Srinagar Jammu and Kashmir V Very Severe

Amanullah Qureshi, Ummer Farooq Pasha and N S Kumar


Table 1.2

2. METHODOLOGY

Figure 2.1 Methodology

2.1. Design Considerations: Limit state method (LSM) is considered for design

purpose

2.1.1. Loads

Dead loads (DL), Live loads (LL), Wind loads (WL), Seismic loads

2.1.2. Wind pressure on walls (Calculations as per IS 875-1987 part-3)

The basic wind speed (Vb) for any site shall be obtained IS 875-1987(3) and shall be

modified to get the design wind velocity at any height (Vz) for a chosen structure. Vz = Vb

k1k2 k3 Where, k1 = probability factor (risk coefficient) shall be obtained from code book of

clause 5.3.1, which indicates that the value of k1 varies with respect to basic wind speed and

the service structure as per Table-1 of page no.11 of IS 875-1987

Table 2.1 k1 factor for different wind speed

Location Basic Wind Speed (m/s) k1 factor

Bengaluru 33 1.05

Vijayawada 50 1.07

k3 = topography factor, The effect of topography factor will be significant at site when

upwind slope Ø>300, Below Ø<30

0 , the value of k3 =1, k3 value is confined in between 1.0-

1.36 for Ø>300, Assuming the upwind slope Ø<30

0, Therefore, k3 =1, From the clause 5.3.2.1,

For our project category of structure is assumed as Category-2, which states “Open terrain

with well scattered obstruction having heights generally between 1.5 to 10 m”, Also, from the

clause 5.3.2.2, class of structure is considered as CLASS-C, which indicates that “Structures

Planning

Drafting (AutoCad)

Modelling (Etabs)

Limit State Method consideration

Analysis

Output Data Reading

Comparison

Conclusion

Location State Wind speed (m/s) Wind Zones

Bangalore Karnataka 33 I

Vijayawada Andhra Pradesh 50 V



or their components such as cladding, glazing, roofing etc, having maximum dimension

greater than 50m”. Cp=1.25. Finally, the wind pressure per unit area “p‟ on the wall is taken

as 1.25p pressure on windward surface and 0.5p suction on leeward surface. When the walls

form an enclosure, the windward wall will be subjected to a pressure of 1.25p and leeward

wall to a suction of 0.5p. The total pressure on the wall swill depends on the internal air

pressure also.

2.1.3. Earthquake load

The time periods in X- and Y direction are calculated using the approximate formula given in

Clause 7.6.2, Ta=0.09*h/√d where, h is height of the building, in m and d is base dimension

of the building at plinth level, in m, along the considered lateral force. For the present

building, time period in X- and Y-direction is found to be 0.86s and 0.92s respectively. The

data used for the seismic analysis are; importance factor, I=1.5, response reduction factor,

R=5 this also shown in below table (Table-5). The different parameters obtained are

considered in later sections with comparison.

Table 2.2 Seismic zone Parameters.

Location Zone Factor

(Z)

Importance

Factor (I)

Response

Reduction Factor

(R)

Time Period (T) In

Seconds

X(s) Y(s)

Bengaluru 0.1 1.5 5 0.86 0.92

Srinagar 0.36 1.5 5 0.86 0.92

2.1.4. General Data and Material Properties

Grade of concrete – M25, M30, M35

Modulus of elasticity E - 5000√fck

Poisson‟s ratio U - 0.2

Unit weight of concrete – 25 KN/m3

Unit weight of brick – 20 KN/m3

Grade of Steel - Fe500

Steel Modulus of elasticity E -200000 Mpa

Steel Poisson‟s ratio U - 0.3

Load combinations as per IS 456-2000: The various load combination considered are

mentioned in the below table.

Table 2.3 Load Combinations

SL.No. Seismic SL.No. Wind

1 1.2 DL+LL+EQx 14 1.2 DL+LL+WLx

2 1.2 DL+LL-EQx 15 1.2 DL+LL-WLx

3 1.2 DL+LL+EQy 16 1.2 DL+LL+WLy

4 1.2 DL+LL-EQy 17 1.2 DL+LL-WLy

5 1.5 DL+EQx 18 1.5 DL+WLx

6 1.5 DL-EQx 19 1.5 DL-WLx

7 1.5 DL+EQy 20 1.5 DL+WLy

8 1.5 DL-EQy 21 1.5 DL-WLy

9 0.9 DL+1.5EQx 22 0.9 DL+1.5WLx

10 0.9 DL-1.5EQx 23 0.9 DL-1.5WLx

11 0.9 DL+1.5EQy 24 0.9 DL+1.52WLy

12 0.9 DL-1.5EQy 25 0.9 DL-1.5WLy

13 1.5 DL+LL



2.1.5. Load Calculations

The wall load of the structure is calculated as follows, For the wall 350mm, Dead load =

0.35*5*20= 35 KN/m2 for the 5m floor height at ground floor. Dead load = 0.35*3*20= 21

KN/m2 for the 1

st to 15

th floor of floor height 3m. For the wall 230mm. Dead load

=0.23*3*20= 13.8 KN/m2. For the parapet wall load of height 1m, Dead load=0.23*1*20=4.6

KN/m2

Table 2.4 Loads value.

Type of loads Load value (KN/m2)

Wall load (350mm,230mm & parapet wall) 35,21,13.8 and 4.6

Floor finish 1.5

Live load 5

Lift load 25

Escalator load 100

Unit Weight of Some Materials Are Given Below (From IS: 875 – Part-I)

• Concrete – Plain = 24.00 KN/m3

• Concrete – Reinforced = 25.00 KN/m3

• Cement mortar = 20.40 KN/m3

• Burnt Brick masonry (BBM) = 19.20 KN/m3

• Plaster = 20.00 kN/m3

• Steel = 78.50 KN/m3

• Water = 10.00 KN/m3

2.1.6. Geometry of the building

Built-up area - 980.085 m2

Utility of building – Shopping mall

No of Stories – G+15

Floor height (GF) – 5m

Floor height (1st to 15

th) – 3m

Depth of foundation – 2m

Thickness of wall – 350mm & 230mm

2.1.7. Auto Cad Plan of the Building

Figure 2.2 AutoCAD plan



3. ANALYSIS AND DESIGN

3.1. Modelling

The analysis and design of buildings are done by using ETABS Software. This topic describes

a general process for creating a model using ETABS.

Initialization options: Display units: METRIC SI, Steel selection data base: INDIAN, Steel

design code: IS 800-2007, Concrete design code: IS 456:2000

Figure 3.1 3D Render View Figure 3.2 Tendon profile

3.2. Analysis

3.2.1. Analysis of Building for Earthquake Loads as per IS 1893(Part-1):2002

Determination of design earthquake forces is computed by the following methods: 1)

Equivalent static analysis and 2) Dynamic Analysis (RSM).

Table 3.1 Seismic Parameters

Variables Parameters

Zone factor of the building (Z) 0.10(II), 0.36(V)

Importance of the building (I) 1.5

Response reduction factor (R) 5

Time Period Ta (S) X-Direction Y-Direction

0.86 0.92

Average response acceleration

coefficient (Sa/g)

X-Direction Y-Direction

1.58 1.47

Soil type Medium soil

Width of building in X-direction 33.45m

Width of building in Y-direction 29.30m

Height of the building 55m

Seismic weight of the building 285904.98 KN (ETABS)

Equivalent static analysis

Table 3.2 ESA Base shear values

Zone Factor (Z) BASE SHEAR (KN)

Conventional Slab Building PT Slab Building

Zone II (0.10) 279570.65 279542.22

Zone V (0.36) 281833.90 281802.22



Table 3.3 ESA Base Reaction Values in X and Y directions

Zone Factor (Z)

BASE SHEAR (KN)


X-Direction Y-Direction X-Direction Y-Direction

Zone II (0.10) 5525.00 5164.68 4521.68 4226.78

Zone V (0.36) 19781.07 18491.00 18931.50 17691.49

Response Spectrum Analysis (RSA): For the present study, the CQC method is considered

and has been analyses using ETABS to compare the Static analysis and Response Spectrum

analysis. The below table shows the base shear obtained from ETABS for all the structures.

Table 3.4 Base shear values in X and Y directions

Zone Factor (Z)

(RSM) BASE SHEAR (KN)



Zone II (0.10) 4630.46 4623.78 3854.44 3762.22

Zone V (0.36) 16558.79 16617.51 16101.56 16092.62

3.2.1. Analysis of Building for Wind Loads as per IS 1875(Part-3)

3.2.2. Base Shear Due to Wind Load

The base reactions due to wind is as follows.

Table-3.5 Base shear due to wind in x and y direction

Zone Factor (Z) and Basic wind

speed (m/s)

BASE SHEAR (KN)

Normal RC Building PT Slab Building


Zone I -33 1563.7676 2014.6611 1463.7687 1947.6611

Zone IV- 50 3294.041 4529.223 3094.0405 4237.223

3.2.2. Analysis of Post Tensioned Slab

The design of post tensioned slab is carried out in accordance to specification of IS 1343-

1980, Prestressing steel, γmp= 1.15, The design load combinations are obtained by

multiplying the characteristic loads by the appropriate partial factor of safety, γf (IS 20.4.2),

which are automated done by ETABS, Ultimate Tensile Stress = 1884 N/mm2 , Nominal area

of strands = 98.7 mm2,

Jacking force = 75% of the Ultimate Tensile Force, Post Tensioned

system: Unbounded, Concrete grade: M40.

4. RESULTS AND DISCUSSION

4.1. Analytical Results

The analytical results obtained from the ETABS software are discussed below:

4.2. Deformed Shapes

Figure 4.1 Deformed Shapes due to Dead Load



Figure 4.2 Deformed Shapes due to Pre-stress

As per the above deformed shapes we can see that the dead load and pre-stress deformed

shapes are opposite in nature, this property of pre-stress contract with the dead load and

reduce efficient tensile stress in service condition.

4.3. Seismic and Wind Analysis Results

4.3.1. Base Shear Due to Earthquake and Wind Load

Base shear in terms of percentage due to earthquake and wind load with structures

conventional slab and post tension slab has calculated and the graphs obtained for base shear

as per above mentioned tables (Table-3.2,3.3,3.4 and 3.5) is shown below.

Figure 4.3 Seismic Base shear

Figure 4.4 Wind Base shear

1.97

7.01

1.65

5.87

1.57

6.51

1.34

5.54

0

2

4

6

8

II V

BA

SE S

HEA

R (

%)

SEISMIC ZONES

BASE SHEAR DUE TO SEISMIC EFFECT IN ESA & RSA ANALYSIS

ESA CONVENTIONAL RSA CONVENTIONAL ESA POST TENSION RSA POST TENSION

0.72

1.6

0.69

1.5

0

0.5

1

1.5

2

I V

BA

SE S

HEA

R (

%)

WIND ZONES

WIND BASE SHEAR

CONVENTIONAL POST TENSION



4.2.2. Maximum Story displacement Due to Earthquake load:

Table 4.1 Displacement due to 1.5(DL+EQY) and 1.5(DL+LL+WLY

Figure 4.5 Displacement Due to Seismic

Figure 4.5 Displacement Due to Wind

0

100

200

300

LR SR S15 S14 S13 S12 S11 S10 S9 S8 S7 S6 S5 S4 S3 S2 S1 GF Base

DIS

PLA

CEM

ENT

(MM

)

STOREY LEVEL

Storey Displacement Due to Seismic in Conventional and Post Tension Slab

Z-II CONVENTIONAL Z-II POST TENSION Z-V CONVENTIONAL Z-V POST TENSION

0

20

40

60


DIS

PLA

CEM

ENT

(MM

)

STOREY LEVEL

Storey Displacement Due to Wind In Conventional and Post Tension Slab

Z-1 CONVWNTIONAL Z-1 POST TENSION Z-V CONVENTIONAL Z-V POST TENSION



4.2.3. Maximum Storey Drift Due to Seismic and Wind load

Table 4.1 Displacement due to 1.5(DL+EQY) and 1.5(DL+LL+WLY

Figure 4.5 Drift Due to Seismic

Figure 4.5 Drift Due to Wind

0

0.002

0.004

0.006


DR

IFT

STOREY LEVEL

Storey Drift Due to Seismic in Conventional and Post Tension slab


0

0.002

0.004


DR

IFT

STOREY LEVEL

Storey Drift Due to Wind in Conventional and Post Tension Slab

Z-I CONVENTIONAL Z-I POST TENSION Z-V CONVENTIONAL Z-V POST TENSION



4.2.4. Storey Shear Due to Earthquake and Wind load

Table 4.1 Storey Shear due to 1.5(DL+EQY) and 1.5(DL+LL+WLY

Figure 4.5 Shear Due to Seismic

Figure 4.5 Shear Due to Wind

0

10000

20000

30000

40000


SHEA

R K

N

STOREY LEVEL

Storeyn Shear Due to Seismic in Conventional and Post Tension Slab


0

2000

4000

6000

8000

LT SR S15 S14 S13 S12 S11 S10 S9 S8 S7 S6 S5 S4 S3 S2 S1 GF Base

DR

IFT

STOREY LEVEL

Storey Shear Due to Wind in Conventional and Post Tension slab

Z-I CONVENTIONAL Z-I POST TENSION Z-V CONVENTIONAL Z-V POST TENSION



5. CONCLUSIONS

i. Base shear due to seismic

Base shear due to dead load, live load and imposed obtained for both structures with

conventional and post tension slab having almost same values with slight variation of

0.1% in zone I and V.

In Conventional slab structures, The RSA method shows 16.19% less base reactions

compare to ESA method in zone-II. Similarly, for zone-V RSA is lagging by 16.29%

with ESA. In post tension slab structures, RSA shows 14.79% less base reactions than

ESA method in zone-II. Likewise, in zone-V RSA is lagging by 14.94% with ESA.

ii. Base shear due to wind

The post tension slab structure having 3.3% less base reaction than conventional slab

structures in wind zone-I.

The post tension slab structure having 6.45% less base reaction than conventional slab

structures in wind zone-V.

iii. Displacement due to seismic load, the post tension slab structures having 32% less

displacement than conventional slab structures in seismic zone-II. Similarly, in zone-V

the post tension structure having 15% less displacement compares to conventional slab

structures.

iv. Displacement due to wind load, the post tension slab structures having 29.17% less

displacement than conventional slab structures in wind zone-II. Similarly, in zone-V

the post tension structure having 12% less displacement compares to conventional slab

structures.

v. The maximum storey drift due to seismic, the post tension slab structures having 22%

less drift value than conventional slab structures in seismic zone-II. Similarly, in zone-

V the post tension structure having 40% less drift compares to conventional slab

structures.

vi. The maximum storey drift due to wind, the post tension slab structures having 23.22%

less drift value than conventional slab structures in wind zone-I. Similarly, in zone-V

the post tension structure having 4.87% less drift compares to conventional slab

structures.

vii. The maximum storey shear due to seismic, the post tension slab structures having

15.41% less shear value than conventional slab structures in seismic zone-II.

Similarly, in zone-V the post tension structure having 2.47% less shear compares to

conventional slab structures.

viii. The maximum storey shear due to wind, the post tension slab structures having

11.04% less shear value than conventional slab structures in seismic zone-II.

Similarly, in zone-V the post tension structure having 3.09% less shear compares to

conventional slab structures.

REFERENCES

[1] Narla Mohan, A.M`Ounika Vardhan, (2017), “Analysis Of G+20 Rc Building In Different

Zones Using Etabs”, Ijpes, Volume 8, Issue 3.

[2] M.Mallikarjun1, Dr P V Surya Prakash, (2016), “Analysis And Design Of A Multi-Storied

Residential Building Of (Ung-2+G+10) By Using Most Economical Column Method”, Ijseat,

Volume 4, Issue 2.

[3] K. Rama Raju, M.I. Shereef, Nagesh R Iyer, S. Gopalakrishnan, (2013), “Analysis And

Design Of Rc Tall Building Subjected To” Wind And Earthquake Loads”, Volume-8



[4] Nlokesh Neddy, N Bijaya Kumar, (2014), “Design And Analysis Of A Commercial Complex

By Using Post Tension Method (Stilt+12floors)” Ijmetmr Issue-11, Volume-1

[5] Kevan.D. Chodvadiya, Ramya. R.S, (2017), „Comparison Of R.C.C And Post-Tension

Building For Seismic‟ Ijaerd, Issue-5, Volume-4.

[6] Jnanesh Reddy R K, Pradeep A R, (2017), “Comparative Study Of Post Tensioned And Rcc

Flat Slab In Multi-Storey Commercial Building”, Irjet, Volume-4, Issue-6.

[7] Tausif J. Shaikh, Swapnil B. Cholekar, Hemant L. Sonawadekar, (2017), “Analysis Of G+20

Rc Building In Different Zones Using Etabs” Volume-8, Issue-3.

[8] Amol S. Rajas, Dr.N.L.Shelke, (2016), “Wind Analysis Of High Rise Building With Different

Bracing Systems”, Ijarset, Vol. 3, Issue 4.

[9] V. G. Mutalik Desai, Mohammad J. Shaikh, (2016), “Comparative Analysis Of Flat Slab And

Post-Tensioned Flat Slab Using Safe”, Iarjset, Volume-3, Issue-8.

[10] Is456:2000, Code For Plain And Reinforced Concrete.

[11] Is1893(Part 1):2002, Criteria For Earthquake Resistant Design Of Structures.

[12] Is875 (Part 1)-1987, Dead Loads

[13] Is875 (Part 2)-1987, Imposed Loads.

[14] Is875 (Part 2)-1987, Wind Loads.

[15] Is1343-1980, Code Of Practice For Prestressed Concrete.

AUTHOR PROFILE

Graduated in the year 2015 from VTU, Belgaum. Presently perusing Master

of Technology in Structural Engineering at Ghousia College of

Engineering, Ramanagaram Also working on this topic for the dissertation

under the guidance of Ummer Farooq Pasha and Dr. N S Kumar.

Ummer Farooq Pasha, Assistant Professor Dept. of Civil Engineering GCE,

Ramanagaram 562159.

Dr. N.S. Kumar, Prof and Director (R & D) is involved in the Research

field related to composite steel columns. He received BE, in Civil

Engineering from Mysore University (1985), ME & Ph.D degrees from

Bangalore University during 1988 & 2006 respectively. He has guided 1

ph.D, 1 M.sc Engineering (By Research) under VTU, Belgaum. Presently

he is guiding 6 Ph.D, scholars and has guided more than 30 M.tech

projects. He has more than 30 years of teaching experience & has published over 130 papers

in National & International journals including conferences.

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