Study On Deformation Influence And Control Measures Of Subway Shield Tunnel By The Side Of Excavation

Along the metro lines of high strength, high density of property development, willinevitably produce a large number of deep foundation pit engineering, the excavation of deepfoundation pit by the side of subway tunnel is one of the most common outside work forms.Because of the large amount of excavation unloading, the change of surrounding soildisplacement field and stress field is bigger, combined with the complexity of the engineeringgeological conditions, the construction process is easy to cause a lot of disease, such as tunnelsegment crack, seepage, seam open and so on. It will affect the subway structure safety andnormal operation.At present, the research about the excavation effect by the side of metro tunnel mailybased on a single project example, and the research of deformation control of foundation pitbased on the shield tunnel deformation control index is not enough perfect, therefore, analysisof the deformation influence law of shield tunnel adjacent to foundation pit, And according tothe shield tunnel protection standards to take corresponding measures to control thedeformation is the key to solve the problem.This article adopts the method of finite element numerical analysis, Systematically studythe excavation effect on lateral deformation of shield tunnel, and analyzed the relateddeformation control measures of metro tunnel engineering and its effect. In this paper, thespecific research work are as follows:(1) Research of the foundation pit engineering examples by the side of Guangzhou metro,analyze the subway shield tunnel convergence deformation and vertical deformationcharacteristics, summarize the method to solve the longitudinal horizontal displacement andvertical settlement of shield tunnel based on Mindlin solution and the theory of Winklerfoundation beam.(2) Based on the finite element method, simulation and analysis of the influence on theshield tunnel by excavation, emphatically analysis of the deformation and internal force ofretaining structure, the horizontal and vertical deformation characteristics and the internalforce of the tunnel.(3) Summarized the deformation of the related influencing factors by the side of subwayshield tunnel, detailed analysis of the horizontal interval of foundation pit, the shield tunnelburied depth, the location and size changes of foundation pit, the excavation depth, theinfluence of the stiffness and uni-axial foundation pit supporting system; Study the influencelaw of the excavation unloading under different influence factors on the lateral deformation of shield tunnel.(4) Proposes the lateral deformation control process of the foundation pit, and calculatethe deformation control values of the foundation pit under certain conditions (horizontalinterval, buried depth, etc.) on the basis of the example in this article. Finally, summary andanalysis of the deformation control measures and its engineering application of the foundationpit by the side of the subway shield tunnel.