Abstract:Relying on Xishanying tunnel of Sanqing expressway, the influence of fault morphology on the deformation of surrounding rock and the stability of supporting structure of the tunnel are explored by using the methods of numerical simulation and field monitoring, and the best reinforcement scheme is put forward. The results show that the maximum value of vault settlement increases in a "logarithmic" curve with the increase of fault thickness. With the increase of fault dip angle, it is distributed in a "parabola" curve, and reaches the maximum when the fault dip angle reaches 90°; and the most unfavorable fault shape is dip angle + thickness (83° +70 m); Then, the numerical model of optimization reinforcement comparison is established, and it is obtained that the pipe shed grouting reinforcement can effectively control the deformation of surrounding rock and inhibit the development of plastic zone. Combined with the measured data, it is found that the difference between the simulated value and the measured value is small, which verifies the correctness of the numerical simulation results.