近远场地震动作用密贴交叉组合地铁车站振动台试验

Shaking table test of the closely-attached intersecting subway station under far-field and near-field ground motion

以北京地铁公主坟换乘车站为背景,开展近远场地震动作用下密贴交叉组合地铁车站振动台试验,通过对模型土体和模型车站结构的动力特性进行分析,研究密贴交叉组合结构地铁车站的地震响应特性。结果表明:在频谱特性不同的近场和远场地震动作用下,土层的地震反应不同,主要频谱成分接近模型地基土基频的近场地震动和中场地震动,对土层的放大效应更明显;与传统的单体车站结构不同,由于上下两个车站间发生相互作用,使得车站结构底板应变幅值大于顶板,边墙结构下端应变幅值均大于上端。

Based on Beijing Gongzhufen interchange subway station, a shaking table test on the closely-attached intersecting subway station was carried out considering the far-field and near-field ground motion. The seismic response characteristics of the closely-attached intersecting subway station were studied by analyzing the dynamic properties of soil and station model structure. The results show that, the seismic response of soil layer is different under the far-field and near-field ground motion with different frequency characteristics. When the predominant frequency of soil layer is close to that of simulated ground motion, the amplification effect on soil layer is more remarkable. Due to the interaction between the upper and lower subway stations, the strain amplitude in station floor is larger than that in station roof, and additionally, the strain amplitude at the bottom of the sidewall is larger than that at the top, which distinguish it from the traditional single subway station.