Seismic response of low-rise steel moment-resisting frame (SMRF) buildings incorporating nonlinear soil–structure interaction (SSI)

Nonlinear behavior at the soil–foundation interface due to mobilization of the ultimate capacity and the associated energy dissipation, particularly in an intense earthquake event, may be utilized to reduce the force and ductility demands of a structure, provided that the potential consequences such as excessive settlement are tackled carefully. This study focuses on modeling this nonlinear soil–structure interaction behavior through a beam-on-nonlinear-Winkler-foundation (BNWF) approach. The results are compared with those from fixed-base and elastic-base models. It is observed that the force and displacement demands are reduced significantly when the foundation nonlinearity is accounted for. Moreover, the foundation compliance is also found to have a significant effect on the structural response.