Soil Structure Interaction Effects on Seismic Performance of Multi-Story RC Buildings with and without Shear Wall

Abstract

Through the structures are supported on soil, most of the designers do not consider the soil structure interaction and its subsequent effect on structure during an earthquake. Recent studies show that the effects of Soil Structure Interaction (SSI) may be detrimental to the seismic response of structure and neglecting SSI in analysis may lead to un-conservative design. Despite this, the conventional design procedure usually involves assumption of fixity at the base of foundation neglecting the flexibility of the foundation, the compressibility of soil mass and consequently the effect of foundation settlement on further redistribution of bending moment and shear force demands. The effects of SSI are analyzed for typical multi-story building resting on raft foundation. Two methods of analysis are used for seismic demands evaluation of the special moment resistant frame buildings: equivalent static load (ESL) and response spectrum (RS) methods using ETABS ultimate 2016 software as per IS 1893:2002 "Criteria for Earthquake Resistant Design of Structures". Numerical results obtained using soil structure interaction model conditions are compared to those corresponding to fixed-base support conditions. The peak responses of natural time period, roof displacement, story drift and base shear are analyzed.