Water inrush from the excavation face often occurs in the current shield construction of metro tunnels. In this study, the\ndiscontinuity of shield tunnel lining and the interaction between the tunnel segments, the grouting layer, and the surrounding\nrock are considered. Based on the 3D nonlinear contact theory, a hybrid model of the shield tunnel is constructed. Considering\nthe fluid-solid coupling effect of water and soil, the influences of different water head differences on the mechanical\nperformance and deformation of segments and joints in the shield tunnel are studied. The water gushing from the excavation\nface leads to vertical convergence of the cross-sectional area of the shield tunnel, and joint opening and dislocation result in\nsharp decrease of the waterproof capacity of joints. Meanwhile, the stress in the vicinity of segment joints increases sharply,\nand local cracks occur in the segment lining. The axial force, shear force, and bending moment in the joint bolt are also\nsignificantly increased. Based on the currentmetro standard and the computational results in this study, an emergency control\ncriterion is put forward by means of controlling the discharge of water: the water head difference over the excavation face is\nrequired less than 4.6 M.
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