SSI Effects on the Behavior of a Low-Rise Load Bearing Masonry Building Including Foundation

The process of soil response influencing the motion of the structure and vice versa is termed as soil-structure interaction. Conventionally, SSI has been considered to pose beneficial effects on the seismic response of a structure because of causing the structure to be more flexible resulting in the increased natural period and enhanced effective damping ratio. These modifications suggest a reduction in base shear demand for a structure as compared to its fixed-base counterpart. This study presents the analyses of a four-storeyed load-bearing brick masonry building. It has been analyzed with the base of the walls as fixed and supported on stiff, medium and soft soil springs. The structure has also been analyzed considering stepped brick masonry strip footing fixed at the base and supported on the same springs as used in the structure. The results are somewhat different than the assumption of fixed-base analyses being always conservative. The study also suggests appropriate modeling to capture maximum response in structural members.