#vertical irregularity

Seismic response of structure is extremely complex because of the non linear behavior soil during earthquakes. Seismic design of structures is generally carried out assuming fixed base ignoring the flexibility of soil. The main objective of the study is to investigate the significance of effect of soil structure interaction on building with mass irregularity. The dynamic contact approach was utilized to simulate pounding between the adjacent buildings. Nonlinear finite element analysis was performed for two adjacent multi story structures with four different configuration representing cases that can exist in reality. The seismic response of the studied cases generally emphasized that ignoring the soil flexibility and or the contribution of the infill panels may significantly alter the response of adjacent structures. Response spectrum analysis has been carried out and the parameters like time period, base shear, roof top displacement and storey drift of the building frames resting over foundation and soil media has been studied.