SENSITIVITY ANALYSIS OF DEFORMATION OF LARGE DIAMETER MUD-WATER SHIELD THROUGH COMPLEX ENVIRONMENT

Shield tunneling can inevitably pass through areas with dense building structures. Especially when the building structure that passes through is constructed for a long time, the foundation is weak, and the stratum deformation exceeds a certain limit, the building foundation is prone to uneven settlement and superstructure the additional deformation. This paper aims to clarify the influencing factors of the formation deformation of the large-diameter muddy water shield tunnel through the complex environment, and to better grasp the law of the formation deformation. It is based on the Wuhan Rail Transit Line 8 Huangpu Road Station-Xujiapeng Station River Crossing Tunnel Project. It uses the element software Plaxis 3D and establishes a three-dimensional finite element model to simulate the construction process. It studies the thickness of the overburden, the support pressure of the excavation surface, the soil loss of the shield shell, and the sensitivity of the shield tail grouting pressure to the surface settlement law. The numerical simulation results are compared and analyzed with the measured values on site. It is found that the finite element calculation results are in good agreement with the measured results, which verifies the validity of the numerical model. The research in this paper can provide method guidance for the subsequent selection of parameters of large-diameter mud-water balance shield.