Influence And Risk Analysis Of Deep Excavation Project Construction On Adjacent Subway Station

In order to solve the increasingly serious traffic problem in the city,large-volume rail transit methods such as subway have gradually emerged.The aggregated business model formed by the subway economy has attracted many enterprises to gather together,so that high-density and high-rise buildings are built or under construction near subway stations.As the foundation of the building,the deep excavation project is directly related to the stability and service life of the building.The deep excavation project will inevitably bring construction risks and environmental effects to the adjacent subway stations.So that the deep excavation project adjacent to the subway stations faces greater technical risks and challenges.This thesis takes the Wuhan City Line Network Center Building project adjacent to the Optics Valley 5th Subway Transfer Station as the background,and the main research work are as follows:(1)Analysis of structural deformation and additional stress of the subway stationCombined with the actual project of the network center building,FLAC 3D is used to establish a three-dimensional numerical model including the deep excavation project,adjacent subway station and surrounding soil.The model focuses on the rigidity of the retaining structure itself and the structural rigidity of the subway station,the part of the retaining structure pile shared between the deep excavation project and the subway.Through the comparison of numerical simulation and monitoring data,the effects of deep foundation pit construction on the displacement and additional stress of the adjacent subway station structure are studied.(2)Analysis of deformation law of retaining structure of deep excavation projectAccording to the comparison results of numerical simulation and monitoring data,the horizontal and vertical displacement and the surrounding surface deformation of the bored cast-in-place pile of deep excavation project's retaining structure are studied,as well as the deformation law of surrounding surface.The shared part of enclosure structure between deep excavation project and subway station,and the part of subway adjacent to the side of deep excavation project are emphatically analyzed.(3)Fault tree risk analysis based on Bayesian theoryThe risk factors of deep excavation project adjacent to the subway station are identified.A fault tree based on Bayesian network was constructed.The probability of the foundation project accident and the direct cause and the indirect reasons of the accident were studied,and then the risk of deep excavation engineering is evaluated,and the application of fault tree based on Bayesian network in the actual engineering of the deep excavation project is studied.