土-结构相互作用的非线性反应

Test Study of Nonlinear Soil-Structure Interaction

为了建立合理的高层建筑在强震作用下的土 结构非线性相互作用分析模型 ,进行了结构 基础 地基体系模型的振动台实验·实验验证了土性非弹性引起的非线性效应以及基础和周围土体局部脱离接触所引起的非线性效应·通过数据分析给出了非线性反应的基本特征 ,为合理估计两种非线性的影响提供了实验基础·分析表明完整的土 结构体系非线性模型中要充分考虑到基础翘离的影响 ,包括翘离引起的基础有效接触刚度的变化以及竖向振动与水平和回转振动三者的耦合效应·

Four groups of shaking table tests were carried out to investigate the nonlinear earthquake response of a one story building with rigid footing: (1)free field test;(2) test of scattering field or the effective input motion;(3) test of SDOF structure model with ground sufface suppported foundation;(4) test of SDOF structure model with buried in soil deposit foundation. Via analysis of experiment data,following conclusions were acquared: (1) Nonlinearities can play a significant role in the test results and with increase of input motion level nonlinear effection increases;(2) In complete model for nonlinear soil-structure interaction(SSI), two kinds of nonlinearitis must be considered:those associated with inelastic soil behavior and those resulting from loss of contact between the foundation and the surrounding soil (uplifting);(3) For the test case the nonlinearitis resulting from uplifting have a more significant effect on the structure response than the nonlinearities associated with inelastic soil behavior does.