地铁交叉结构近场地震反应振动台试验研究

为探究地铁交叉结构地震响应规律,以常见的双隧道下穿单层车站结构为背景进行地震反应振动台试验,试验模型箱采用柔性箱,结构为微粒混凝土浇筑,并按实例工程配筋率用镀锌钢丝网进行配筋,考虑上下结构密贴、上下结构存在夹层土及单体车站三种工况进行水平方向加载,通过对交叉工况与单体车站结构应变、侧墙土压力及加速度反应分析对比,底部隧道结构的存在对传来的地震波具有吸收作用,使上部车站的地震响应减弱,减幅随夹层土体厚度的增加而减小。

Shaking Table Model Test of Subway Cross structure under Near field Ground Motion

In order to explore the rules of cross structure seismic response in metro, a shaking table test is carried out in background of common structure with parallel tunnels going through the single layer subway station. Flexible model box is used in the test. The structures are poured with micro concrete and reinforced with galvanized steel wire according to the ratio used in instance. Horizontal loading are carried out the model by considering three operating conditions. Based on the analysis of structure strain, soil pressure and acceleration response in cross structure and only subway station, the following conclusions are drawn: the tunnel under the station can absorb part of the furniture seismic wave; the seismic response of top station is reduced; the weaken amplitude is diminished with increase of the thickness of laminated soil.