international journal of research and innovation€¦ · *citation: p.swetha, "design and...

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION

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91

Subject: Civil and Construction Engineering IJRICCE

DESIGN AND ANALYSIS OF MULTI STORIED STRUCTURES USING

STATIC NON LINEAR ANALYSIS

P.Swetha1, K. Mythili2, G.Venkat Ratnam3.

1 Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological & Research Academy,

Hyderabad, India.

2 Associate Professor, Department of Civil Engineering, Aurora's Scientific Technological & Research Academy,

Hyderabad, India.

3 Associate Professor, Department of Civil Engineering, Aurora's Scientific Technological & Research Academy,

Hyderabad, India.

Abstract

The main objective of the research work presented in this thesis is to provide a systematic procedure to assess the

behavior of a structure symmetrical and unsymmetrical

In plan during the seismic excitation using nonlinear static analysis (pushover) have been performed on the same

structure. The literature pertaining to pushover analysis is reviewed. The pushover analysis adopted in the present

study is on similar lines with the procedure presented by Ashraf Habibullah and Stephen Pyle using ETABS V 9.7

structural analysis software. The effect of earthquake force in an idealized G+4 story building under maximum

earthquake zone, with the help of pushover analysis has been investigated and the results were compared in terms of

base shear, displacement, spectral acceleration, spectral displacement and effective damping and effective time period

.to strengthen the symmetric and un symmetric RCC framed buildings` steel braces are included by using retrofitting

method.

The present structure is studied using the evaluation procedures provided in ATC-40 and FEMA-356 documents and

IS 1893:2002. From the above studies it has been observed that nonlinear pushover analysis provides a good estimate of in elastic

deformation demands and also reveals weakness that may remain hidden in an elastic analysis.

*Corresponding Author:

P.Swetha, Research Scholar,

Department of Civil Engineering,

Aurora's Scientific Technological & Research Academy,

Hyderabad, India

Email: [email protected]

Year of publication: 2014

Paper Type: Review paper

Review Type: peer reviewed

Volume: I, Issue : II

*Citation: P.Swetha, "Design And Analysis of Multi Storied Structures Using Static Non Linear Analysis" International Journal of Research and Innovation (IJRI) 1.2 (2014) 91-97

NEED FOR THE INVESTIGATION

Low to medium height reinforced concrete frame

buildings with masonry infill are common in urban

India. All these buildings in general designed to resist

gravity loads and hence can’t be expected to resist the

latest seismic provisions. Earthquake causes shaking

of the ground in unspecified directions. The horizontal

shaking along X and Y directions remain a matter of

concern. Structures designed for gravity loads, in

general may not be able to safely sustain the effects of

horizontal shaking due to earthquakes. Hence it is

necessary to ensure the strength of the structure

against horizontal earthquake effects.



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OBJECTIVES OF THE STUDY

The primary objective of this work is to study the

seismic response of RC framed building. The effect of

earthquake force on building in a symmetric and UN

symmetric building under maximum earth quake zone,

with the help of push over analysis has been

investigated.

In the present study the main objective is the

investigatethe impact of steel bracings in improving the

seismic capacity of RC buildings.

The main objective of undertaking the present study

are as follows:

1) To analyze a RC framed building both symmetric

and UN symmetric using pushover analysis procedure,

with ETABS v 9.7 for ascertaining the seismic load

carrying.

2) To compute the seismic response of building in

terms of base shear, spectral acceleration, spectral

displacement and roof displacements.

3) To study the effect of the steel bracings as a method

of retrofitting.

4) The increasing in base shear.

5) The reduction in amplitude of maximum displace-

ments.

Performance Point

Collapse Prevention Level (CP):

Building Performance Level’s

PRESENT STUDY

Description And Plan For Symmetrical Building

Description And Plan For Unsymmetrical Building

STRUCTURAL SYSTEMS OF THE BUILDING

storey G+4

Slab thickness 125mm

Beam dimensions 230 mm x 450 mm

Column dimensions 230mm x 450 mm

Exterior wall 230 mm

Interior wall 150 mm



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General Data Collection

Variable Type Reference

Type of soil Medium soil IS 1893:2002

Type of founda-

tion

Isolated footing ----

Seismic zone V IS 1893:2002

Pushover Analysis Using Etabs V9.7:



94



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DISCUSSION ON RESULTS

Observations under Pushover Curve

The Structures has been given in a Pushover curve for

the Structures was graphically generated for both the

symmetric and un symmetric Building i.e. Structure

without steel bracings and Structure With steel

bracings as shown in the Fig. And Fig.respectively, It

has been observe from the Fig. 5.14 and Fig. 5.15 that

the base shear was monolithically increasing with the

Displacement. And for the Drift the Maximum Base

Shear was observed to be 796.22 kN and 1560.99 kN

respectively.

Observations under Capacity spectrum curve

Observations under Pushover curve

Observations under Capacity spectrum curve

HINGE PATTERNS FOR SYMMETRIC STRUCTURE

WITHOUT STEEL BRACINGS AND UN SYMMETRIC

STRUCTURE WITH STEEL BRACINGS



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CONCLUSIONS

After having perform the pushover analysis on two

different buildings with and without steel bracings

following conclusions are drawn

• In symmetrical building based an the performance

point obtained from pushover curve (fig no page no

)and the same building with steel bracings (fig no page

no) the value of base share is found increased by %

and the amplitude and displacement found by reduced

%

• In un symmetrical building based on the performance point obtained from pushover curve (fig no page no )and the same building with steel bracings

(fig no page no) the value of base share isfound

increased by % and the amplitude and dis-

placement found by reduced %

• Based on the above study it is felt that

introduction of steel bracings is one proven

method of structural retro fitting

REFERENCES

1. A. Kadidand A. Boumrkik, (2008), “Pushover analysis of reinforced concrete frame structures”, at Department of Civil Engineering, University of Banta, Algeria, Asian journal of civil engineering (building and housing) vol. 9, No. 1 pp 75-83.

2. ASCE, (2002), “Standard Methodology for Seismic Evaluation of Buildings”, Standard No. ASCE-31.

American Society of Civil Engineers, Reston, Virginia.

3. Ashraf Habibullah and Stephen Pyle, (1998),

“Practical three dimensional non-linear static pushover analysis”, Structures Magazine, winter.

4. Ashraf Habibullah S.E., (2008), “Physical object

based analysis and design modelling of shear wall systems using etabs”, at Computers & Structures, Inc., Berkeley, California.

5. ATC NEHRP, (1997), “Commentary on the

Guidelines for the Seismic Rehabilitation of Buildings”, FEMA 274 Report, prepared by the Applied Technology Council, for the Building

Seismic Safety Council, published by FEMA, Washington, D.C.

6. ATC-40, (1996), “Seismic evaluation and retrofit of

concrete buildings”, Vol.1, Applied Technology Council, Redwood city, CA.

7. ATC, (2006), “Next-Generation Performance- Based

Seismic Design Guidelines: Program Plan for New and Existing Buildings”, FEMA 445, Federal Emergency Management Agency, Washington, D.C.

8. Biggs JM. Book, (1964), “Introduction to structural

dynamics”, USA, Publisher: McGraw-Hill. 9. BjörkHauksdóttir, (2007), “Analysis of a reinforced

concrete shear wall”, M,Sc thesis.

10. Bracci J.M., Kunnath S.K. and Reinhorn A.M., (1997), “Seismic Performance and Retrofit Evaluation of Reinforced Concrete Structures”, Journal of Structural Engineering, ASCE, Vol. 123, 3-10.

11. Chintanapakdee C. and Chopra A.K., (2003),

“Evaluation of Modal Pushover Analysis Using



97

Generic Frames”, Earthquake Engineering and Structural Dynamics, Vol. 32,417-442.

12. Chopra A.K. and Goel R.K., (1999), “Capacity –

Demand Diagram Methods for Estimating Seismic Deformation of Inelastic Structures: SDOF Systems”, PEER Report 1999/02, Pacific Earth-quake Engineering Research Centre, University of California, Berkeley.

13. Chung- Yue Wang and Shaing-Yung Ho, (2007), “Pushover analysis for structure containing rc walls”, at The 2nd International Conference on Urban Disaster Reduction, Taipei, Taiwan No-vember, 27-29.

14. CPAMI., (2002), “Code requirements for structural

concrete”, Taiwan: Construction and Planning Agency, Ministry of the Interior, CPRMI publisher.

15. Computers & Structures, Inc., (2002), “SAP 2000 –

Integrated Building Analysis & Design”, User Interface Manual,” .

16. Computers & Structures, Inc Website: www.csi-berkeley.com

17. Edward L. Wilson, (2002), “Three-dimensional static and dynamic analysis of structures”, at Computers and Structures, Inc.1995 University Avenue Berkeley, California 94704 USA.

18. Fajfar P. and Fischinger M., (1987), “Nonlinear Seismic Analysis of R/C Buildings: Implications of a Case Study”, European Earthquake Engineering, 31-43.

19. FEMA 273, NEHRP, (1997), “Guidelines for the Seismic Rehabilitation of Building”, prepared for Federal Emergency Management Agency, Wash-ington DC.

20. FEMA 356, (2000), NEHPR guidelines for “Pre standard and commentary for the seismic re-habilitation of buildings”, prepared for Federal Emergency Management Agency, Washington DC.

AUTHORS

P.Swetha

Research Scholar,



Hyderabad, India.

K. Mythili

Associate Professor,



Hyderabad, India.

G.Venkat Ratnam

Associate Professor, Department of Civil Engineering,

Aurora's Scientific Technological & Research Academy, Hyderabad, India.

international journal of research and innovation€¦ · *citation: p.swetha, "design and...

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