Nonlinear behavior simulation of soil-structure interaction system via real-time hybrid testing

Soil-structure interaction (SSI) can potentially compromise structures that are subjected to seismic excitation. In recent years, real-time hybrid testing (RTHT) has been used to study soil-structure interaction. However, a very simple soil model has been adopted in existing hybrid testing, which cannot simulate nonlinear effects in a soil-foundation system under vigorous seismic shaking. To study the stability and accuracy of RTHT for nonlinear SSI and to evaluate the dynamic impact of soil nonlinearity on an SSI system, real-time hybrid shaking table testing was performed based on full-state control via simulation (FSCS), in which the soil-foundation system was simulated using a macroelement model. The results demonstrate that FSCS-controlled RTHT is an effective approach for investigating nonlinear SSI. The nonlinear characteristics of the numerical substructure had little influence on the stability and accuracy of RTHT for nonlinear SSI systems, but the nonlinear characteristics of the soil had a positive effect on the structural seismic response. An effective dynamic testing method was proposed for the SSI studies.