Numerical Simulation of the Construction Process of a Slurry Balance Shield Traversing Under an Existing Tunnel

The Dapu Road double-track tunnel is an important auxiliary project of the Shanghai Expo 2010; a numerical simulation of this project using a 3D nonlinear finite element method is studied in this paper. The model of a slurry balance shield along a curved path traversing under an existing tunnel with complex geometric features was built and the construction process of a slurry shield was simulated by using Drucker-Prager elastoplastic constitutive and applying a slurry pressure. The model was solved by using the Newton-Raphson method and was proved to be reliable by comparing measured and calculated settlement. By analyzing the influences of the ground surface and existing tunnel, the displacement and stress of the existing tunnel were obtained.