Abstract:Taking the high-level radioactive waste repository in Belgium as background,based on the comprehensive analysis of the main factors influencing the stability of surrounding rock during tunnel excavation,an elastoplastic seepage flow-stress coupling analysis model is set up according to the effective stress analysis method;and a 3D nonlinear finite element method is put forward to simulate the excavation of tunnel by shield machine. The distributions of pore pressure,stress field,displacement field of surrounding rock and the lining stress of concrete segment are analyzed in detail. The results can provide references to construction and field measurement of mudstone shield tunnel.