Some Considerations in Seismic Analysis of Spatial Structure Acounting for Soil-Structure Interaction

Abstract

The seismic analysis of spatial structure in the last 40 years was developed from the static to the dynamic analysis, from the elastic analysis to the elasto-plastic analysis, from the deterministic to the stochastic analysis, and from the uniform seismic excitation in one dimension to the non-uniform seismic excitation in multi-dimensions. The practices show that the model of the spatial structure should be built not only including the roof structure, but the supporting structure and even the foundation as well. Seismic analyses for the nuclear plant, the offshore flatform and the high-rise building have shown that the seismic response of those structures considering the soil-structure interaction (SSI) effect varied a lot compared with that of rigid-connected model. However, few studies have been done for seismic analysis of spatial structures accounting for soil-structure interaction. In present paper, the 3D BNWF(Beam On Nonlinear Winkler Foundation ) SSI model for the shallow foundation and the 3D dynamic p-y model for the deep foundation, the earhtquake input model, the elasto-plastic hysteritic model suitable for the superstructure and the substructure are put forward for the seismic analysis of spatial structure. The research will lay a good foundation for the 3D nonlinear analysis of spatial structure incoporating the SSI under strong earthquake shaking and further promote the performance based design of the spatial structure.