地铁盾构隧道下穿既有高铁隧道施工影响研究

Study on impact of subway shield tunneling under the existing high-speed railway tunnel

以某地铁下穿高铁隧道工程为背景,利用有限元方法,分析地铁与高铁隧道垂直距离和地铁施工顺序对既有高铁隧道受力和变形的影响。研究结果表明:地铁隧道施工期间既有高铁隧道变形主要为整体下沉,沉降最大位置位于地铁左右隧道中间线仰拱处;地铁隧道施工过程中高铁隧道衬砌拱腰处拉应力增量最大;地铁隧道左右线分别开挖比同时开挖时对高铁隧道产生的沉降小;地铁隧道距离高铁隧道越近高铁隧道变形和应力增量越大;建议地铁隧道下穿高铁隧道施工时其垂直距离宜大于0.71D。

In the background of a subway tunnel project, this paper analyzes the impact of the vertical distance between the subway and the high-speed railway tunnel and the subway construction sequence on the stress and deformation of the existing high-speed railway tunnel by using the finite element method. The results show that the deformation of the existing high-speed railway tunnel is mainly the overall subsidence during the construction of the subway tunnel, and the biggest settlement is located in the invert of the middle line of the left and right tunnels of the subway. During the subway tunneling, the tensile stress increment at the arch center of the lining of the high-speed railway tunnel is the biggest, and the impact of excavation of the left and right lines of the subway tunnel separately is smaller than that of the simultaneous excavation on the high-speed railway tunnel. The smaller distance between the subway tunnel and the high-speed railway tunnel, the smaller deformation and stress increment. It is suggested that the vertical distance should be greater than 0.71 D when the subway tunnel passes through highspeed railway tunnel.