Inelastic lateral seismic response of building frames under influence of bedrock depth variations incorporating soil-structure interaction

In this study, a fifteen storey moment resisting building frame is selected in conjunction with a soft clayey soil, representing soil class Ee, according to Australian Standards. Different bedrock depths including 10 m, 20 m, and 30m are employed in the numerical modelling using finite difference software FLAC 2D. The above mentioned frame has been analysed under two different boundary conditions: (i) fixed-base (no soil-structure interaction), and (ii) flexible-base (considering soil-structure interaction). Inelastic dynamic analyses under influence of different earthquake records for three mentioned bedrock depths are conducted, and the results in terms of inelastic lateral deflections and inter-storey drifts for the above mentioned boundary conditions are compared and discussed. The results indicate that the bedrock depth variations play a significant role in inelastic lateral seismic response of the building frame under the influence of soil-structure interaction. As the bedrock depth increases, lateral deflections and inter-storey drifts of the structures increase. The mentioned effects can change the performance level of the structures from life safe to near collapse or total collapse.