EFFECT OF SOIL-STRUCTURE INTERACTION ON SEISMIC DEMANDS OF STRUCTURES IN DESIGN PROCEDURES

In this research, both kinematic interaction (KI) and inertial interaction (II) effects of soil-structure interaction (SSI) on seismic demands of structures are investigated by applying ground motions recorded at soil site E that SSI effect is considerable. Carrying out a parametric study, the structure and underlying soil are modeled as a Single Degree Of Freedom (SDOF) structure with elasto-plastic behaviour and a simplified 3DOF system, based on the concept of Cone Model, respectively. The foundation is considered as a rigid cylinder embedded in the soil. Then the soil-structure systems are analyzed under 15 ground motion recorded at site class E and a comprehensive parametric study is performed for a wide range of non-dimensional parameters defining SSI problem. Consequently, comparing the results with and without inclusion of SSI effects reveals that both II and KI play an important role in analyses or design procedures and ignoring them may cause un-conservative results in cases of deep embedded foundation and slender structures.