地铁盾构隧道与邻近深基坑开挖相互影响分析

Analysis of Interaction between metro shield tunnel and adjacent deep foundation pit excavation

为了研究地铁盾构隧道对邻近深基坑围护结构在不同施工工况下的受力和变形特征的影响,深基坑开挖施工对邻近盾构隧道衬砌结构受力和变形特征的影响,基及坑、周围土体和邻近隧道结构的相互作用机理,本文采用岩土有限元分析软件MIDASGTSNX,对盾构隧道侧穿邻近深基坑开挖工程进行仿真模拟,计算得到了不同工况条件下地下连续墙的水平侧移和受力变化特点、内支撑的受力特点,并将其与无邻近隧道时的计算结果进行对比,对基坑开挖前后邻近隧道衬砌结构的受力特征进行了分析。通过计算分析得到了深基坑开挖与邻近盾构隧道结构相互作用的力学特征,研究结果可以为深基坑和盾构隧道设计施工中的风险控制提供借鉴。

In order to study the influence of the subway shield tunnel on the stress and deformation characteristics of the retaining structure of the adjacent deep foundation pit under different construction conditions,the influence of the deep foundation pit excavation on the stress and deformation characteristics of the adjacent shield tunnel lining structure,and the interaction mechanism of the foundation pit,the surrounding soil and the adjacent tunnel structure,the shield tunnel passing through the adjacent deep foundation pit excavation engineering is simulated by using the geotechnical finite element analysis software MIDASGTSNX.The horizontal lateral displacement and stress variation characteristics of diaphragm wall and the stress characteristics of internal support under different working conditions are calculated,and compared with the calculation results without adjacent tunnel.The stress characteristics of adjacent tunnel lining structure before and after the excavation of the foundation pit are analyzed.Through calculation and analysis,the mechanical characteristics of the interaction between the deep foundation pit excavation and the adjacent shield tunnel structure are obtained.The research results can provide reference for the risk control in the design and construction of deep foundation pit and shield tunnel.