SSI效应对隔震结构地震响应的影响分析

摘要

Through analyzing the data of shaking table model tests of isolated structure on fixed ground base and soil ground base, the effects patterns of soil-structure interaction (SSI) on dynamic characteristic and earthquake response of isolated structure are studied. The results show that effects of SSI on foundation motion of isolated structure are great, the peak value of foundation motion is smaller than that of the free field, and the spectral component of foundation motion is different. Effects of SSI on acceleration amplification factors of floors of isolated structure are significant, and the acceleration amplification factors of floors is greater than those on fixed ground base. One of main factors leading to the acceleration response of floors increasing is swing motion caused by rotation of isolated layer, which is the constitutions of acceleration amplification factors of floors.%通过对刚性地基和土性地基上隔震结构体系振动台模型试验的数据进行对比分析,研究了土-结构动力相互作用(SSI)对隔震结构地震响应的影响规律.研究结果表明:SSI效应对隔震结构基底地震动影响较大,隔震结构基底地震动的峰值小于自由场地震动的峰值,其频谱组成与自由场地震动不完全相同.SSI效应对隔震结构楼层加速度反应有明显影响,SSI效应使隔震结构楼层加速度放大倍数较刚性地基时增大.楼层加速度组成分量中隔震层转动引起的摆动分量是导致土性地基上隔震结构楼层加速度反应增大的主要因素之一.