土-结构相互作用体系振动台试验数值模拟

Numerical modeling of shaking table testing of soil-structure interaction system

运用土-结构动力相互作用有限元三维分析软件SASSI2000,对一个土-结构动力相互作用体系振动台模型试验进行了模拟计算。首先对振动台模型试验作了简单的介绍,进而详细介绍了试验的建模方法。对试验的两种地基条件、3条地震波输入、3个加速度峰值水平及两个输入方向的各种组合工况进行了计算,并将试验结果与计算结果进行了比较。结果表明:计算模型较好地模拟了相互作用体系在地震荷载下的反应性状,计算结果与试验结果吻合较好;同时表明,土-结构相互作用效应对结构地震反应有很大的影响。

Numerical modeling of a model of soil-structure interaction (SSI) system is performed by SASSI2000 pro- gram. The shaking table testing and simulation methods are introduced in this paper. The superstructure is regarded as 3-D finite elements connected at nodal points. The 3-D beam elements with three translational and three rotation- al DOFS per node simulate the beams and columns of superstructure. Four-node shell elements simulate the floors of superstructure and artificial mass is distributed over every shell elements. The surface footing of structure is simu- lated by 3-D solid elements with three translational DOFS per node. The site consists of semi-infinite viscoelatic horizontal layers on a rigid base. The dynamic nonlinear effects of soils is considered by using equivalent linear method. The iterated soil properties obtained from SHAKE program are used for SASS12000 analysis. The seismic responses of superstructure, under the condition of two sorts of grounds, three seismic events, three maximum ac- celeration levels and two input directions, are calculated by SASSI2000 program. Comparison between test results and calculated results indicated that the analysis model is good to simulating the performance of SSI system under seismic excitation. So, the test results are coincident with calculated results approximately.