Impact Assessment of SSI on the Structural Performance of RC Buildings under Lateral Forces

Abstract

The performance of RC multistory buildings is significantly impacted by the interaction of soil-structure under lateral loads. The vulnerability of foundation soil to seismic vibration or wind force on the superstructure is typically overlooked in the structural design. This study examines the effects of a multi-story RC building's soil-superstructure interaction (SSI) under the impact of wind and seismic forces. This study implements the linear Winkler foundation model by assuming that the subsurface soil was medium soil and clay soil, idealized with a spring system to analyze the SSI effect. The self-weight, live-load, wind-load, and earthquake are used as the design forces in the ETABS software to carry out the 3-D simulation. The IS 1893:2016 and IS 875:2015 code provisions are used to carry out the EL and WL analyses. In this study, the structural performance of buildings is characterized in terms of storey displacement, drift ratio, base shear, and time-period. The maximum displacement for the SSIE-clay model has increased by 25.13% and 15.60% under earthquake forces compared to the FBE and SSIE-medium soil models. The fundamental period for building rests in medium soil and fixed bases models under EQ forces decreased by 15.63 and 10.36 percent when compared to the clay base model. In comparison to the FBW model under WL analysis, the maximum base shear of the FBE model under EQ analysis exhibits a 35.38 percent increment. When compared to earthquake forces, this study's findings show that the behavior of buildings with SSI is less vulnerable to wind forces.