地铁车站液化上浮响应及抗浮措施研究

地铁车站的地震液化上浮是地下结构常见的灾害之一，对处于液化场地的地铁车站需增加抗液化及抗浮措施。通过数值分析的方法对比分析了抗拔桩和隔离墙2种抗浮措施的作用机理及作用效果，研究了车站的上浮位移、地表变形和周围土体超孔隙水压比等动力响应。结果表明:设置抗拔桩可提供抗拔力，隔离墙可有效阻挡液化土的流动，因此地铁车站的上浮位移明显减小；抗拔桩的长度进入非液化土层时抗浮效果最佳；隔离墙的抗浮效果随着与车站主体的距离增加而减弱。通过该项研究，可为液化场地中地铁车站的抗浮设计提供一定的理论参考。

Study on uplift behavior and anti-liquefaction measures for subway station during seismic loadings

Uplift behavior of underground structure is a typical liquefaction disaster caused by earthquake,which indicates that anti-liquefaction and anti-floating measures should be implemented to the underground subway station located in liquefiable fields.Two anti-floating measures,tensile piles and barrier walls,are analyzed and compared.To study the action mechanism and effect of anti-floating measures,the uplift displacement of station,ground deformation and excess pore water pressure ratio of surround soil are investigated.The results show that tensile can provide downward tensile force,while barrier walls can intercept the spreading of liquefied soil.Therefore,the uplift displacement of station is decreased obviously.The anti-floating effect is optimal in the case that the tensile pile is driven into non-liquefaction layer,either the barrier walls is near the station structure.This study can provide certain reference to the anti-floating design of underground station located in the liquefiable field.