Simulation of tunnel excavation in fractured rock masses using extended finite element method

The extended finite element method (XFEM) is a new numerical method for modeling discontinuity. XFEM is used to simulate the tunnel excavation with the presence of discontinuities. This method greatly eases the simulation of fractured rock masses as no remeshing is required. Numerical examples are analyzed to demonstrate the efficiency of the XFEM technique in tunnel excavation problem It is observed from these simulations that joints have great influence on the deformations stress distributions around the tunnel. And numerical results also indicate that the influence of a joint to the underground tunnel stability is strongly dependent of the joint dips and locations.