Effect of Soil-Structure Interaction on Seismic Behavior of Mid- and Low-Rise Buildings

This study investigates the effect of soil-structure interaction (SSI) on seismic behavior of mid- and low-rise residential buildings considering linear and nonlinear behavior of structural members. For this purpose, four- and seven-story buildings representing a majority of existing building stock were used. The outcomes indicate that there are significant variations in displacement demand estimates depending on ground motion records, modeling approaches (linear/nonlinear structural modeling and fixed-base or SSI), and soil types. The findings in this study evidently indicate that linear fixed-base models are highly sensitive to dynamic amplification. Therefore, their use may result in inappropriate displacement demand estimates. If the soil amplification and nonlinear modeling are considered, the differences in the average displacement demand estimates of both the fixed-base and SSI models are negligible. Besides, the displacement demand estimate for stiffer soils is independent of modeling. This study underlines that the linear structural modeling includes SSI or the fixed-base model has to be used with nonlinear structural modeling in order to have acceptable demand estimates for the seismic evaluation of the reinforced concrete residential buildings. (c) 2021 American Society of Civil Engineers.