可液化土-高层结构地震相互作用振动台试验  

Shaking Table Testing on High-rise Buildings Considering Liquefiable Soil-structure Interaction

作　　者：李培振[1] 程磊[1] 吕西林[1] 任红梅[1] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《同济大学学报（自然科学版）》2010年第4期467-474,共8页Journal of Tongji University:Natural Science

基　　金：国家"九七三"重点基础研究发展计划资助项目(2007CB714202);国家自然科学基金重大研究计划重点资助项目(90815029);国家自然科学基金资助项目(50578124);上海市青年科技启明星计划资助项目(07QA14054)

摘　　要：进行了可液化土-高层结构地震相互作用的振动台试验,试验采用柔性容器以减小边界影响,采用饱和砂土作为模型土.试验中再现了液化场地土中高层结构的震害现象.得出的主要规律有:相互作用体系的振型曲线与刚性地基上结构的振型曲线明显不同;随着振动次数的增加,体系的频率降低,阻尼比增大;砂土对地震动可起滤波和隔震作用;当最初加速度峰值到达前,砂土层中的孔压比存在负值;震后土中孔隙水压力不一定随振动的停止而立即开始消散,在短期内可能继续增长;桩身应变幅值呈桩顶大、桩尖小的分布;桩土接触压力幅值分布规律与输入激励地震大小有关.Shaking table model test was made on high-rise buildings with a consideration of the liquefiable soil-structure interaction with the saturated sand soil as model soil. A flexible container was fabricated to minimize the box effect. Macro-phenomena of high-rise building in ground of soil liquefaction due to natural earthquake were reproduced well. Test results show that the mode shape of the system is different from that of the structure on the fixed base in that there are rocking and swing at the foundation. The natural frequency of interaction system decreases and the damping ratio of soil increases with the increase of the shaking. The liquefied soil can filter and isolate vibration. Transient minus pore pressure occurs. Pore water pressure does not always dissipate in short time immediately after the excitations, but it may keep on increasing too. The distribution of the strainamplitude along the pile is the shape where the large strain is at the top of the pile and the small strain is at the tip of the pile. And the distribution of the contact pressure on the pilesoil interface is related to the excitation magnitude.

关 键 词：地震相互作用 振动台试验 高层结构 可液化土 

分 类 号：P315.97[天文地球—地震学]