Numerical Analysis of Face Stability during Shield-Driven Tunneling under Groundwater Table

When the water table is above the tunnel, the seepage force acting on the tunnel work face is an important factor on workface instability. In this paper, according to similarity of the fundamental equations between the temperature field and seepage flow field, the Numerical Simulation of the seepage flow field is carried out by the FEM software ANSYS function of temperature field analysis. The seepage force was calculated first in the flow field and then was added to the stress field. Subsequently, the water head difference outside and inside of the chamber was conducted as the parametric study, which provide ample evidence of the crucial role in the tunnel working face stability played by seepage forces. Based on the above procedure, the authors want to propose a newly method of face stability analysis considering the seepage flow which can make the design more suitable for underwater shield tunnel excavation.