Study on Failure Mechanism and Support Design of Tunnel Surrounding Rock

Abstract

Taking a tunnel as the engineering background, this paper focuses on the mechanism of large deformation of soft rock, the design and optimization of supporting technology, aiming at the problem of large deformation of tunnel surrounding rock. By means of numerical simulation, the failure mechanism of structural large deformation of layered surrounding rock is deeply analyzed and studied. The tunnel is simulated with different support parameters to find more reasonable support parameters and optimize the existing support. The results show that the displacement of surrounding rock increases with the increase of upper load. When the roof load is less than 0.7 MPa, the vertical displacement of the sensitive block tends to be stable after a certain period of time; When the top plate load is 0.7 MPa, the vertical displacement of the roof sensitive block cannot converge, so some reinforcement measures must be taken at this time. When the tunnel is supported by bolts, the longer the length of bolts, the better the effect will be. 3m anchor length should be selected for support, and other support methods should be added to control tunnel deformation.