实地挖河对地铁隧道结构的影响分析

Analysis of Influence of On-site Excavating River on Structure of Subway Tunnel in Shanghai

摘要:

上海市地铁线路繁多，河道建设工程常遇到已建地铁线路，在地铁线路正上方按规划实地开挖河道，卸土工程量大，会引起地铁隧道结构产生不利影响。以实际工程为例，通过荷载变化、回弹变形、隧道变形曲线曲率、相对变形等计算和有限元软件模拟，分析及研究施工对已建地铁运行影响。采取“河底抗浮底板+河底土体加固（三轴搅拌桩）+抗隆起桩（钻孔灌注桩）”的方式加以保护地铁隧道结构，减轻河道开挖对已建地铁的运行影响，为同类型项目建设提供参考。

Abstract:

There are so many subway lines in Shanghai. The river construction project often meets the existing subway lines. The planned on-site excavating river directly above the subway line will cause the adverse impact on the structure of subway tunnel because of large unloading work. Taking an actual project as an example, by the calculation and finite element simulation of load change, elastic deformation, tunnel deformation curvature radius and relative deformation, the influence of construction on the operation of built subway is analyzed and studied. The method of "river bottom anti-floating floor + river bottom soil reinforcement (three-axis mixing pile) + anti-heave pile (bored pile)" is adopted to protect the structure of subway tunnel, reduce the influence of river excavation on the operation of the built subway, and provide a reference for the construction of similar projects.