Study on the Reinforcement Effect of Surface Rebar Mesh for Cracked Lining in Railway Tunnels with Finite Element Numerical Simulation

Abstract

In view of the designers ' doubts about the waste of resources caused by excessive reinforcement of lining crack damage and the actual effect of measures such as plastering mortar and crack repair under the action of quality defects and environmental degradation, based on the point of view of inhibiting crack expansion, the reinforcement measures of protective reinforcement — surface rebar mesh has been put forward, and the reinforcement effect of surface rebar mesh under the action of surrounding rock pressure has been studied by finite element software. The results indicate that Reinforcement bars can improve the stress concentration at the crack tip, reduce the first stress of the structure and improve the safety factor of the structure. The strength of the face reinforcement system also did not exceed the material's ultimate limit. Due to the weak shear resistance of the retaining bars and the complexity of the formation mechanism of cracks with large depth, the retaining bars are not suitable for the reinforcement of cracks with a depth of 0.5 times the lining thickness or more.