软土地层顶管施工对运营铁路线路变形影响分析

An Analysis of the Effect of Pipe-Jacking Construction on the Deformation of Railways in Soft Soil

以天津市南水北调中线滨海新区供水工程为案例,对顶管下穿铁路线及切割CFG桩基进行分析。首先汇总各地穿越既有铁路、地铁结构变形控制要求,总结本工程铁路线路保护标准,并依托数值计算软件在仅考虑掘进阶段外侧触变泥浆的情况下分施工工况对地层位移、轨面竖向位移、桩基位移等内容进行数值分析,得出线路竖向位移较大、轨面沉降差较小,同时被切割的CFG桩基水平位移较小的结论,最后对既有铁路结构提出保护措施及建议,确保铁路结构安全可靠。

With the water supply project of the Binhai New Area on the middle route of Tianjin South-to-North Water Transfer Project as a practical example, jacking pipes under an existing railway and cutting the CFG pile foundation are analyzed in the present paper, which first collects the various deformation-controlling requirements for projects under-crossing existing railways and subway structures everywhere, then sums up the protection standard for the railway route of this project. and makes numerical analyses of the ground displacement, the vertical displacement of the rails and the displacement of the pile foundation with the help of numerical calculation software. It is found that the longitudinal displacement of the railway route is comparatively large and the settlement of the rails is relatively little. Meanwhile, it is also foundthat the level displacement of the cut CFG pile foundation is comparatively little. Finally, a few protection measures and suggestions for existing railway structures are put forward in the paper to ensure the safety and reliability of existing railway structures.