COMPARATIVE STUDY OF SITE SPECIFIC SEISMIC RESPONSE OF MULTI STORY FRAME STRUCTURE WITH DIFFERENT ENGINEERING BED LAYER

Abstract

Earthquakes are natural hazards under which disasters are mainly caused by damage or collapse of
buildings and other man-made structures. During an earthquake, seismic waves radiate away from the source
and reach the ground on which these seismic waves produce shaking. The surface ground shaking causes severe
damage to the structures, which depends on characteristic of subsurface soil. The seismic force on building
depends on peak ground acceleration and time period of building as specified in IS: 1893 (Part I)-2002 in terms
of zone factor (Z) and spectral acceleration (Sa/g). Codal provisions usually specify standard normalized
response spectra for different soil types irrespective of local conditions. Therefore for a realistic design of
earthquake resistant structures site-specific detailed investigation is necessary.
In the present study ground response analysis of eight bore hole of Dholera SIR is carried out using one
dimensional equivalent linear analysis. Site specific response spectra are developed using Edushake software.
Acceleration time history recorded at El Centro 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 spectra are used to evaluate response of multi-storied frame structures using
ETABS software. The base shear is calculated for 5, 10, 15, 20 and 25 storied regular frame structures for
various sites. Also shear forces, bending moments and shear forces for ground floor columns of the structures
are obtained using site specific response spectra. The analysis result of site specific response spectrum analysis
is compared with that obtained considering IS: 1893 (Part I)-2002 response spectrum.