Analysis and Design of Shear Wall Building Using Site Specific Response Spectrum

Abstract

Earthquakes cause destruction to life and property in catastrophic proportions. As a result, the main objective of earthquake engineering is to design structures that would suffer minimum damage in the event of an earthquake. In the design process, the most difficult and crucial step is to specify the design seismic load.

The forces on building depend on peak ground acceleration and time period of building. Subsoil condition is responsible for the amplification of ground motion. Amplification may increase or decrease the value of spectral acceleration coefficient (Sa/g). So, analysis using code specified response spectrum may underestimate or overestimate seismic forces in building, which lead to unsafe or uneconomical building.

The aim of present work is to study the effect the site specific response spectrum on analysis of shear wall frame building. Present study includes ground response analysis of eleven sites of Ahmedabad city using one dimensional equivalent linear analysis based software ProSHAKE. Acceleration time history recorded at Passport office building of Ahmedabad on 26th January 2001 Bhuj Earthquake is considered as input motion for different sites to get acceleration time history of ground as well as response spectra. The site specific response spectrum for various sites are then compared with the standard response spectrum plot given in IS: 1893 (Part I)-2002.

The Site specific response spectrum and acceleration time history analysis of shear wall building is carried out using ETABS software. Analysis result i.e. Time period, base shear and design forces in shear wall, obtained by site specific response spectrum analysis, time history analysis and IS: 1893 (Part I)-2002 response spectrum are compared. From these analysis results it is observed that Acceleration time histories on ground and response spectra are influenced by local sub soil characteristics. Design forces in shear wall are governed by Time history analysis and response spectrum analysis in case of certain buildings.

Structural wall is more effective as an earthquake resistance element when it is situated at an advantageous position. The parametric study is carried out using parameter as the shear wall position and height of building using ETABS.

In this study an attempt is made to understand the effect of site specific response spectrum on behavior of shear wall building using Pushover analysis. A Pushover Analysis is used to obtain the inelastic deformation capability of building. The Pushover analysis is carried out using nonlinear version of ETABS software.

Finally the study has been made to understand the effect of site specific response spectrum on design of shear wall and its foundation.

The content of major project is divided in to various chapters. Chapter 1 is of a general nature and it serves to introduce the topic. Chapter 2 gives the literature review carried out during work. Chapter 3 presents methods for analysis of site specific ground response analysis. It also includes the development of site specific response spectrum and site specific time history at different sites of Ahmedabad. Chapter 4 deals with the site specific response spectrum analysis of shear wall building using ETABS. This chapter also includes the behavior of shear wall and shear wall frame interaction. In chapter 5, site specific acceleration time history analysis of shear wall frame building are presented. Chapter 6 presents the effect of site specific response spectrum on different shear wall positioning in buildings. Chapter 7 is concerned with the nonlinear response of shear wall frame building considering site specific response spectrum. Effect of site specific response spectrum on design of shear wall and its foundation are presented in chapter 8. Finally summary, conclusion and future scope of work are given in chapter 9.