盾构隧道下穿对高铁桥梁稳定性影响分析

Influence Analysis While Metro Shield Tunnelling Underneath on the Stability of High-speed Railway Bridge

以深圳地铁某区间盾构隧道下穿广深港高铁桥梁为例,采用三维有限元数值方法模拟了地铁先掘进左线和先掘进右线两种工况,对比分析两种工况下高铁桥墩顶位移。结果表明:受高铁桥下净空限制,在无法施工隔断桩防护的情况下,由于左线隧道覆土厚度较大且距高铁桥梁略远,地铁盾构先掘进左线时高铁桥梁产生的变形值较小,对桥梁稳定性影响较小,且变形满足高铁桥梁变形相关规定,不影响高铁运营安全。该结论对类似工程有一定的借鉴意义。

Taking a shield tunnel in Shenzhen Metro which is under the Guangzhou Shenzhen Hong Kong high-speed railway bridge as an example, the three-dimensional finite element numerical method is used to simulate the two conditions, namely left line heading first and right line heading first, and the comparative analysis is made for the top displacement of the high-speed bridge pier. The results show ： owing to the limit of the space of the high-speed rail bridge, the protection of the partition pile can not be constructed, and due to the larger covering thickness and the far distance to bridge, the deformation of high-speed railway bridge is smaller and has less impact on the bridge stability when the first left line of the shield tunnelling which meets the requirements of high-speed railway bridge, and does not affect the operation safety of high-speed railway. The conclusion has some reference significance for similar projects.