Influence of Soft Soil Shear Strength on the Seismic Response of Concrete Buildings Considering Soil-Structure Interaction

摘要

Influences of undrained shear strength on seismic response of moment resisting concrete building considering soil-structure interaction (SSI) have been studied. A 15-storey building model resting on class E_e soil with different values of undrained shear strength has been simulated through FLAC~(3D). Fully nonlinear dynamic analysis under four different earthquakes including two far-field and two near-field recordings has been conducted by direct method and results in terms of base shear, maximum lateral displacement, inter-storey drift and spectral acceleration have been compared and discussed. Results indicate that by increasing the undrained shear strength of the subsoil, the superstructure experiences extra base shear under earthquake excitations due to SSI. Furthermore, the maximum lateral displacements and inter-storey drifts of the superstructure increase by adopting higher values for the undraied shear strength of the subsoil. It is concluded that practicing engineers should treat soil properties gained from field or laboratory tests with extreme care when dealing with numerical based seismic design of the soil-structure systems.