基坑开挖对邻近地铁隧道的变形影响分析

THE ANALYSIS ON THE DEFORMATION OF ADJACENT METRO TUNNEL DUE TO FOUNDATION PIT EXCAVATION

为分析基坑工程不同因素对邻近隧道变形的影响,以上海某邻近区间隧道基坑工程为例建立三维有限元模型,通过实测数据的分析以及与数值模拟结果的验证,分别分析地下连续墙插入比、刚度、近距离小坑开挖深度、隧道埋深等因素对隧道变形的影响,结果表明适当提高地下连续墙插入比、刚度,可降低基坑施工对隧道变形的影响,且基坑设计开挖深度宜小于隧道轴线埋深,研究成果可为指导基坑设计施工提供参考。

In order to analyze the influence of different factors of foundation pit engineering on the deformation of adjacent tunnels,a three-dimensional finite element model of a foundation pit engineering adjacent to the tunnel in Shanghai is established.Through the analysis of the measured data and the verification of the numerical simulation results,the influences of the penetration ratio and stiffness of the diaphragm wall,the excavation depth of the short distance pit and the depth of the tunnel on the tunnel deformation are analyzed.The results show that the influence of foundation pit construction on tunnel deformation can be reduced by increasing the penetration ratio and stiffness of diaphragm wall.For reducing the influence on tunnel deformation,it is suggested that the design excavation depth of foundation pit should be less than the buried depth of the tunnel center.The relevant results may provide the refer⁃ence for guiding the design and construction of foundation pit.