Analysis of Deformation Characteristics of Shield Tunnel Section under Environmental Load

Research purposes: The shield tunnel of urban subway can easily cause the deformation of the lining structure under the action of environmental load. In order to analyze the structure of city shield tunnel deformation causes and deformation characteristics, based on the basic vector concept, the quantitative analysis of the deformation size and direction of the tunnel structure is presented, and combining with the finite element analysis method, the structural deformation form of shield tunnel under different environmental loads is simulated, to verify the correctness of the tunnel deformation description method. Research conclusions:(1)In the general stratum with no weak sliding surface, the size and direction of structural deformation are closely related to the form of environmental load, and the largest inward deformation of the structure occurs in the direction of the largest environmental load.(2)The shield tunnel is in the stratum with weak sliding surface. The maximum deformation of lining structure is not the same as the maximum loading direction, but it is related to the sliding direction of the sliding surface. The deformation magnitude of the lining end point passing through the tunnel cross section has a catastrophic feature. (3)The research results are of great theoretical value to reveal the deformation mechanism of the urban shield tunnel and to predict the environmental load changes around the tunnel. © 2021, Editorial Department of Journal of Railway Engineering Society. All right reserved.