The Influence of Adjacent Buildings on Seismic Motion Field Considering Building-Site Interaction

Due to the interaction between buildings and sites during an earthquake, buildings can impact the seismic motion in their proximity. In this study, a nonlinear finite element model of building-site interaction considering soil nonlinearity is established by numerical simulation. The building-site interaction effects on the ground motion field around buildings are investigated under various site conditions and building dynamic properties. The seismic response spectra analysis results indicate that: (1) Buildings noticeably alter seismic response spectra nearby, generally reducing them at short periods and amplifying them at long periods. This effect is more pronounced on soft soil sites with lower shear wave velocities, resulting in up to 48% reductions compared to free-field conditions. (2) The presence of buildings changes the fundamental period of the building-site interaction system. Larger building masses on sites with lower shear wave velocities increase disturbances in seismic response spectra across all periods. (3) The building-site interaction effect on ground motion spectra diminishes gradually with increasing distance from buildings in surrounding areas. The larger building mass extended the influence range of building-site interaction, and this influence is more pronounced on soft sites. (4) Soil nonlinearity significantly increased the spatial variability and extent of building disturbances, especially for ground motions with long periods.