Stability Analysis of Tunnel Face under the Influence of Shield Tunneling Inclination Angle

In order to investigate the stability of the longitudinal inclined tunnel face under the influence of any inclination angle, using the Hoek-Brown strength criterion as an example, considering the influence of the longitudinal inclination angle of the tunnel, using spatial discretization and point generation techniques, the existing 3D active passive failure model of the tunnel face was improved, and the ultimate support pressure of the active passive failure of the inclined tunnel face was solved. A three-dimensional active passive failure model for the inclined tunnel face under the nonlinear Hoek-Brown criterion was established. By comparing and analyzing the calculation results of this model with the numerical simulation results, the rationality of the three-dimensional active passive failure model of the inclined tunnel face under the nonlinear Hoek-Brown criterion established in this paper is verified. The results show that: The maximum error between the three-dimensional active passive failure model of the inclined tunnel face established in this paper and the numerical simulation results under the nonlinear Hoek-Brown criterion is less than 5%, and the fitting effect is good, which is suitable for the stability analysis of the inclined tunnel face. The inclination angle between the tunnel and the horizontal plane caused by any deviation in elevation is an important factor affecting the stability of the tunnel face, and special attention should be paid in practical construction, providing effective theoretical guidance and reference for the safety of shield tunneling similar to tunnel construction.