Seismic Soil Structure Interaction of Buildings with Rigid and Flexible Foundation

Amar R Chougule, S S Dyavanal

Abstract: The effect of soil-structure interaction is generally ignored in the design process of low-rise buildings resting on shallow foundations though it has been shown that ignoring such effect may lead to unsafe seismic design. When a structure is subjected to an earthquake excitation, it interacts the foundation and soil, and thus changes the motion of the ground. It means that the movement of the whole ground structure system is influenced by type of soil as well as by the type of structure. An attempt has been made in this paper to study the effect of Soil-structure interaction on multi storeyed buildings with various foundation systems. Also to study the response of multi storeyed buildings subjected to seismic forces with Rigid and Flexible foundations subjected to seismic forces were analysed under different soil conditions like hard, medium and soft. A conventional G+6 storied building when rests on different soils is chosen for the study. The influence of soil-structure interaction is compared with the results obtained when the structure is assumed to be fixed at the base.

Keywords: Soil structure interaction, Natural period, Base shear, Fixed base, Flexible base, Soil stiffness, Storey drift