高铁盾构隧道施工对邻近桩基影响数值分析

以天津-潍坊高铁双线海河隧道下穿既有市政桥梁工程为依托,为探究盾构施工过程对地表沉降及市政桥梁桩基变形的影响规律,采用有限元分析软件Midas/GTS NX 对盾构开挖全过程进行模拟。模拟结果表明,高铁隧道开挖至市政桥梁附近时地表沉降速率变大；地表沉降量最大的位置并不是桥梁桩基附近；在地质条件不好的情况下,隧道穿越桩端位置时,桩基础容易发生向内的倾斜,同一排桩的位移值基本一致,桩端的水平位移大于桩顶,且同一个墩台下的前排桩的水平位移小于后排桩、竖向位移大于后排桩。

Numerical Analysis on Influence of High-speed Railway Shield Tunneling on Adjacent Piles

Taking the Haihe tunnel of Tianjin-Weifang High-speed Double-line railway under-crossing the existing municipal bridge as the background,the whole process of shield construction was simulated by using the finite element software Midas/GTS NX and the influence of the shield construction on the surface settlement and municipal bridge piles deformation was analyzed. According to the numerical simulation results, the rate of ground settlement speed increased when the High-speed railway tunnel excavation to municipal bridge; the location of the maximum surface settlement is not near the bridge piles; the piles are prone to inward inclination when the tunnel passes through the end of the piles in bad geological conditions; The displacement value of the same row of piles is basically the same, and the horizontal displacement of the end of the pile is greater than the top of the pile. The horizontal displacement of the front pile under the same pier platform is less than that of the rear pile, and the vertical displacement is greater than that of the rear pile.