地铁盾构穿越高速公路桥台及路基案例分析

A Case Study of Metro Shield Tunnel Crossing under Highway Bridge Abutment and Subgrade

为确保地铁盾构隧道穿越不停运的高速公路时,高速公路的结构安全,文章以佛山地铁2号线花-仙区间盾构隧道下穿佛山一环高速公路桥台及路基工程为例,利用盾构施工影响机理及土体松动原理,对穿越过程进行了三维有限元仿真建模分析。数值计算结果显示,盾构隧道穿越引起的路基最大沉降为9.14 mm,桥台桩基最大水平位移为1.06 mm,能够满足相关结构安全和变形控制要求。通过实际监测结果与模拟计算结果的对比,验证了分析方法的可行性。通过采取现代化动态施工和监控联动措施,将盾构下穿的影响控制在了合理的范围之内,可为同类工程提供参考。

In order to ensure the structural safety of the highway when a metro shield tunnel crosses under a traffic non-stop highway,this paper takes the Flower World station-Xianyong station running tunnel of Foshan Metro Line 2 as an example,which passes under the abutment and subgrade of the Foshan First Ring Expressway,and carries out a 3D finite element simulation modeling analysis of the crossing construction process by using the impact mechanism of shield construction and the principle of soil loosening.The numerical calculation results show that the maximum settlement of the subgrade caused by the crossing construction of the shield tunnel is 9.14 mm,and the maximum horizontal displacement of the pile foundation of the abutment is 1.06 mm,which can meet the relevant requirements for structural safety and deformation control.The feasibility of the analysis method is verified by comparing the actual monitoring results with the simulation calculation results.The impact of shield under-passing is controlled within a reasonable range by adopting linkage measures of modern dynamic construction and monitoring,which can provide a reference for similar projects.