Soil-structure interaction analysis using a 1DT-3C wave propagation model

International audienceThe soil-structure interaction (SSI) is generally neglected for seismic design of ordinary buildings. A modeling technique is proposed to facilitate the integration of SSI in building design, considering rocking effects and the shallow foundation deformability. The proposed technique is suitable when the soil can be considered as horizontally layered. The one-directional three-component wave propagation is numerically simulated in a T-shaped horizontally layered soil domain assembled with a three-dimensional (3D) frame structure. A 3D soil model is used until a fixed depth and a 1D model is supposed to be a sufficient approximation in deeper soil layers. The 1DT-3C wave propagation approach is inspired by the consideration that SSI is detected in the near-surface soil layers. The proposed modeling approach is verified by comparison with a fully 3D model for vertical propagation in horizontally layered soil and periodic lateral boundary condition. The 1DT-3C wave propagation modeling technique is used to investigate the building response and SSI effects that vary with the frequency content of seismic loading and building-to-soil frequency ratio, respectively