可液化场地地铁车站结构地震破坏特性振动台试验研究  

Shaking table test on seismic failure characteristics of subway station structure at liquefiable ground

作　　者：陈国兴[1] 左熹[1] 王志华[1] 杜修力[2] 周恩全[1] 

机构地区：[1]南京工业大学岩土工程研究所,江苏南京210009 [2]北京工业大学建筑工程学院,北京100022

出　　处：《建筑结构学报》2012年第1期128-137,共10页Journal of Building Structures

基　　金：国家自然科学基金重大研究计划项目(90715018;90715035);国家公益性行业科研专项(200808022);江苏省高校自然科学重大基础研究项目(08KJA560001)

摘　　要：模拟大震主、余震地震动作用,开展了石膏模型的三层三跨地铁地下车站结构地震破坏特性的振动台试验,测试与分析了可液化地基土的加速度、振动孔压、地表震陷和模型车站结构的加速度、水平向相对位移、应变、侧墙动土压力反应及其空间效应,再现了喷水冒砂、地表裂缝、震陷及模型车站结构上浮、构件裂缝及局部破损等宏观震害现象。研究结果表明:在主震作用时,地基土液化持续时间长、振动孔压消散趋势不明显,地基土的加速度放大效应降低,液化地基呈现出显著的减震与低频集中效应;余震作用时地基土振动孔压的消散较为明显;模型结构峰值加速度反应沿高度增大,侧墙动土压力反应沿高度呈中间小、两端大的分布模式;模型结构中柱的峰值应变反应最大,且中柱左右两侧的峰值应变与损伤程度沿高度呈S形分布;可液化地基土与模型车站结构的地震反应存在显著的空间效应现象。Based on the plaster model of a three-story and three-span subway station on liquefiable ground, a series of shaking table tests on the seismic failure characteristics were conducted under the main shock and aftershock ground motions. With respect to the foundation, the following characteristics were discussed including the acceleration, dynamic pore water pressure, and earthquake-induced settlement of ground surface. The model subway station structure was concerned with the following features including the acceleration, the relative horizontal displacement, the strain, dynamic soil pressure on the side wall and its spatial effects. According to the tests, the sand and water spewing phenomenon, the earthquake-induced settlement and ground crack were successfully reproduced. Meanwhile, the floating of structure, member cracks and local damages were observed during the tests. Under the main shock ground motion, there appears a longer liquefaction duration time and the trends of pore pressure dissipation are not obvious, and the acceleration amplification effect of the soil is decreased. The foundation soil shows a remarkable shock absorption and concentration effect with low frequency. Under the aftershock ground motion, the dissipation of pore pressure in foundation soil becomes obvious. The peak acceleration of the structure increases with the height. The dynamic soil pressure on the side walls is smaller in the middle and larger at both ends. In addition, the interior column achieves the maximum value of peak dynamic strain. The peak strain and damage degree on both sides of interior column exhibit an “S” type distribution along the height. The seismic responses of both the foundation soil and the model subway station structure exhibit a remarkable spatial effect.

关 键 词：地铁地下车站结构 可液化场地 地震作用 振动台试验 破坏特性 空间效应 

分 类 号：TU375.4[建筑科学—结构工程] TU354