土-结构动力相互作用对橡胶支座隔震结构的影响

采用子结构法,建立了频域内土-结构动力相互作用下的橡胶支座隔震结构的分析模型及相应的运动方程,通过数值仿真2个具有埋置刚性基础的剪切型基础隔震结构的地震反应,并选用多种地基土,较为系统地分析计算了不同地基土参数组合下结构的隔震效果和地震响应.结果表明,设置橡胶支座隔震层可以削弱土-结构动力相互作用对结构动力特性的影响,减小结构相对于场地运动的楼层位移和基底位移.同时,土-结构动力相互作用使橡胶支座隔震效果有所降低,且影响程度与上部结构刚度成正比,与地基土刚度成反比.

Responses of Rubber Bearing Isolation Structure Considering Soil-Structure Dynamic Interaction

By means of the substructure approach in the frequency domain, equations of motion of the rubber - isolated structures are established considering the soil-structure dynamic interaction. The seismic responses of two shear-type base-isolated structures with an embedded rigid rectangular foundation are numerically simulated, and the influences of the different rigidities of soil on the effect of the base isolation and the seismic responses of the structure are investigated. It is concluded that rubber bearing isolation can reduce the dynamic characteristics of structures and reduce displacement of floor and basement relative to ground. Meanwhile, considering the dynamic soil-structure interaction may reduce the isolation effect of the rubber-isolated structures and the effect level is in direct proportion to the stiffness of the superstructure and inverse proportion to the stiffness of foundation soil.