Effects of Soil Structure Interaction on Reinforced Concrete Framed Structures

Abstract

This study proposes to highlight effects of soil structure
interaction on the Reinforced Concrete (RC) framed
structures. In this study, the seismic responses of the
structures are observed considering soil structure
interaction (SSI) from its actual soil condition. Here, two
preexisting structures are taken for the study. One is
residential building and the other is hospital building with
two basements. Taking into account the actual soil
condition of each building site, this study provides idea on
the soil structure interaction on different kinds of buildings.
Direct and substructure approaches are used to incorporate
soil structure interaction in the analysis. The properties of
springs are calculated for different standard penetration test
(SPT) values and springs are assigned for footing for the
substructure approach. Entire soil-foundation-structure
system is modelled and analyzed in single step for direct
approach. Static analysis, response spectrum analysis and
time history analysis (THA) are done in order to find the
variations in natural periods, base shears and deflections of
the structures by incorporating soil flexibility as compared to
structures with conventional fixed base.