An Overview of Foundation Structure Interaction

During earthquake the behavior of any structure is influenced not only by the response of the superstructure, but also by the response of the soil beneath. Structural failures in past have shown the significance of Soil-structure interaction (SSI) effects. The present study focuses on SSI analysis of a symmetric 13 story RC Space frame shear wall building over soft soil and subjected to seismic loading. The transient analysis of structure -soil-foundation system is carried out using ETAB software. Earthquake motion in time domain corresponding to Zone Vof IS 18932002 designs. Seismic coefficient method is used to excite the model of soil-structure system. For integrating the SSI effect, one type of soils based on values of elastic modulus of soil, Poisson ratio and shear modulus are considered. Responses in terms of variation in natural period, base shear, deflection, and column forces, obtained from the analysis of the SSI model are compared with that obtained from conventional method assuming rigidity at the base of the structure. The results show that the SSI effects are significant in altering the seismic response full shear wall at central bay and basement wall below plinth in combination is the alternative for minimizing the effects of SSI.