Analysis of Safety Factors of Twin Tunnels with Small Spacing by Strength Reduction FEM

摘要

A safety factor of twin tunnels with small spacing has been greatly concerned. The safety factors of surrounding rock and lining are analyzed in this paper. The former is obtained by strength reduction FEM, and the latter is calculated according to the requirements in the tunnel supporting structure. The Cuntan Tunnel in Chongqing is used as an example calculated safety factors. The results well reflect stability variations and security reserve situations of surrounding rock and the lining during the construction, and can be used as a basis for stability evaluation.