A Parametric Study on Soil-Structure Interaction of RC Building with Different Base Conditions

Soil-structure interaction refers to the effects of supporting soil medium on the motion of structure and its subsequent response during earthquakes. Multi-storey buildings could have multiple basements for varied functions, viz. automobile parking, boiler system, air-con system, electrical distribution system and cable TV distribution purpose. This study involves soil-structure interaction analysis of a multi-storey building with multiple basements supported on stratified soil medium. The building has ten floors above the ground and 2 below. Response spectrum analysis has been performed on the structure assuming fixed base, flexible base due to homogeneous soil and flexible base due to non-homogeneous or layered soil beneath the foundation using finite element software SAP 2000. Soil properties are included in building model by continuum approach to perform soil-structure interaction analysis. Seismic response of multi-storey building, viz. lateral displacement, storey drift and modal time period is studied for Indian seismic zone V as per I.S. 1893–2002. Presence of non-homogeneous soil beneath foundation of multi-storey structures with basements increases the seismic response of the structure significantly compared to homogeneous soil beneath foundation.