地下通道施工引起的下方地铁隧道变形研究

Research on the Deformation of Metro Tunnel Caused by the Construction of Underpass

本文介绍了采用U形管幕+预制箱涵顶进法施工地下通道的案例,该地下通道上跨已运营的地铁区间盾构隧道。文章采用有限元数值分析的方式,分析了管幕及箱涵施工全过程对地铁隧道变形的影响,并介绍了该案例的实际实施效果。研究结果表明:①相比于传统的明挖法,采用U形管幕+预制箱涵顶进法施工引起的地铁隧道变形明显减小。②管幕+箱涵实施期间,受反复卸荷、加载等影响,下方地铁隧道的竖向位移会产生一定的波动,但绝对值均很小。③管幕+箱涵施工期间,箱涵顶进阶段引起的地铁隧道变形最大,隧道呈隆起变形。

This paper introduces a case of using U—shaped pipe curtain+precast box—culvert jacking method to construct the underpass,which cross metro shield tunnels.In this paper,the influence of the whole construction process of pipe curtain and box culvert on the deformation of subway tunnel is analyzed by means of finite element numerical analysis.It also introduces the practical effect of the case.The results show that:1)Compared with traditional digging method,the deformation of metro shield tunnel can be effectively controlled by using U-shaped pipe curtain+precast box—culvert jacking method.2)During the construction of the underpass,the vertical displacement of the subway tunnel below will fluctuate due to repeated unloading and loading,but the absolute value is very small.3)During the construction,the maximum deformation of subway tunnel is caused by the jacking stage of box culvert.