Numerical Simulation Analysis Of The Stability For The Structure Of Rock And Support In Large-span Tunnel

Hanjialing tunnel lies in Pulandian , Dalian city. It is a newly-built one-cave and 4-lane large-span highway tunnel in Shenyang to Dalian expressway widen-rebuilding project. The biggest inner outline width of the tunnel is 19.44m,its biggest clear height is 9.92m, the biggest excavated width in construction is 21.242m,and the excavated height in the middle axis of the tunnel reaches to 15.52m. Its excavated area heads the list in one-cave tunnel at present, and it is also the largest span highway tunnel in China now. Due to the engineering design experience of large-span tunnel is short of similar one in the nation, and the currently "Design Specification for highway tunnel" can not guide the so large-span design of tunnel yet. For example, how to define that " loading - structure "calculation model recommending in the currently Design Specification and loading of less crowded surrounding rock etc.,all these are very different from the design concept and soul of new Austrian tunneling method (NATM). Therefore how to analyze and solve the stability of surrounding rock and support structure of Hanjialing tunnel during excavating and supporting just becomes the key technology problem in tunnel design and construction.That this thesis closely combines with the large-scale emphatic engineering construction project in the nation. I have especially consulted with technical data of large-span tunnel, and analyzed some tunnel of nation and abroad. On the foundation of the above-mentioned, through geology investigated this thesis has defined some necessity of physics parameter and classification of surrounding rock of tunnel. This thesis also has defined the structure size and construction organization scheme under the different surrounding rock conditions of tunnel. Finally this thesis uses Mohr-Coulomb destruction rule as the criterion of surrounding rock turns into plasticity, and uses the two-dimension finite element method to solve the problem that surrounding rock and support structure stability classified IV that has become plasticity with linear elasticity. What has gained that served as the design and construction in Hanjialing large-span tunnel, and will provide the important reference basis to other tunnels.