局部液化区对地铁区间地震响应影响分析

为了研究局部液化区对邻近区间结构地震动力响应的影响,通过数值仿真模拟,分析区间隧道顶部存在局部液化区时区间隧道的动力响应规律,并针对设计过程中采用的增大管片配筋和增强纵向连接螺栓的抗液化措施进行探讨。经分析,局部液化区对邻近的隧道结构有较大影响,靠近液化区一侧隧道结构内力在地震液化工况下相比非地震液化工况时有显著增加;局部液化区对邻近隧道内力的影响范围沿隧道轴向约为3D(D为局部液化区的等效直径);隧道下穿局部液化区时,地震时隧道结构会发生上浮,但局部液化区对隧道结构位移影响不大;增大管片配筋和增强纵向连接螺栓刚度可以有效地控制管片内力,防止因内力过大引起的管片破坏。

Effects of Partial Liquefaction on Seismic Dynamic Response of Subway Structure

For studying seismic dynamic response of the subway structure with partial liquefaction,numerical simulation is performed to analysis the law of dynamic response of the tunnel with partial liquefaction on the top, and anti-liquefaction measures are discussed such as increasing the tube reinforcement and enhancing the longitudinal stiffness of connecting bolt. The results of analysis show that partial liquefaction has a great impact on the adjacent tunnel structure,and the internal force of the tunnel structure near the liquefaction zone significantly increases subject to soil liquefaction. The scope of influence of partial liquefaction to tunnel internal force is about 3D( D is the diameter of partial liquefaction); the tunnel structure floats up when the tunnel passes under the partial liquefaction zone.However,the effect of partial liquefaction on displacement of tunnel structure is small. Increasing the segment reinforcement and enhancing the stiffness of the longitudinal connecting bolt prove to be effective to control the segment internal force,thus,preventing segment damage caused by internal force.