DEFORMATION CHARACTERISTIC OF TUNNEL SURROUNDING ROCK UNDER COMPLEX CONDITIONS

Research purpose: Xinqidao liang Tunnel is the largest highway-tunnel cross section in Gansu province, with complicated geological conditions. The distribution pattern of the deformations of the surrounding rock of tunnels under complex conditions is studied, so as to provide guidance for the design and execution of the excavation and reinforcement of tunnels, which is one of the most important aspects of information-aided construction. Research method: A large amount of convergence measurement cross-sections are installed in the job site and long-term monitoring and measurement are executed. This paper analyzed convergence data of surrounding rock in the tunnel and effects. Research result: It is pointed that deformation of surrounding rock has the characters of time pertinence and space pertinence. The deformations of the surrounding rock contain 3 stages: rapid-deforming stage, slow-increasing stage and nearly-stable stage. The deformations of the surrounding rock mass of Xinqidaoliang tunnel has such features as uniform deformation, rapid convergence, small deformation and crown settlement larger than the horizontal convergence. Research conclusion: These deformations are functions of many factors such as geological conditions, technology and ambience. Results indicate that the surrounding rock of the tunnel is good with high self-supporting capability, the design and execution technology of the excavation and reinforcement of the tunnel is scientific and rational and the reinforcement structure is strong. The analysis of rock deformation feeds back construction, and produces satisfactory effects.