Analysis of nonlinear soil-structure interaction effects: 3D frame structure and 1-Directional propagation of a 3-Component seismic wave

摘要

In this paper, a finite element modeling technique, taking into account the effects of soil-structure interaction (SSI) is proposed for structural analysis and design. The one-dimensional model of a nonlinear multilayered soil profile is assembled with a multi-story multi-span frame model and the dynamic equilibrium problem is solved directly. The one-directional propagation of three-component seismic waves (1D-3C) is modeled taking into account the SSI, in the case of rigid shallow foundation and negligible rocking effects.The 1D-3C wave propagation model provides the three components of motion at the base of the frame structure, allowing the reduction of mesh size and computation time, compared with a fully three-dimensional model, and avoiding modeling difficulties to realize a reliable three-dimensional soil domain, related among others to boundary conditions.The proposed model allows the analysis of those structural dynamic features, seismic wave and local soil stratigraphy, that produce changes in the ground motion at the surface. The model reproduces well expected phenomena, in the case of layered soil with increasing nonlinearity and for different inertia distribution in the frame structure. SSI combined with seismic site effects is analyzed in a Japanese soil profile, using as seismic loading a 3C record of 2011 Tohoku earthquake.