Stability Analysis And Treatment Measures Of Fault Fracture Zone In Yushan Tunnel

Complex geological problems frequently encountered fault fracture zone during tunnel construction, etc., may be severe and caused heavy economic losses. In this paper, Yushan tunnel construction site, carried out through the tunnel ahead of forecasts fault fracture zone, stability analysis, The Monitoring and Treatment Measures. Analysis of the results of the tunnel through the fault fracture zone Construction Safety provides technical guidance, provide a theoretical basis and engineering experience in similar projects, have more practical value of the works. The main findings are as follows:(1) We detected the position and scale of the fault fracture zone in front of the tunnel face by comprehensive prediction work, which also found the broken surrounding rock and weak interlayer with water at the frontage. And obviously, we can concluded the surrounding rock has a poor stability.(2) Pipe roof construction, advanced small pipe and through the tunnel ahead of Bolt in fault fracture zone is very effective governance, through rational design and elaborate construction of Yushan tunnel through the fault fracture zone were processed, monitoring results show that pipe roof construction, advanced small pipe and lead anchor in yu tunnel project, fully meet the design requirements.(3) Yushan tunnel through fault fracture zone segment numerical simulation results show that the transverse tunnel stress focused on the tunnel on both sides of the wall, the direction toward the inside of the tunnel, so to squeeze inside the tunnel sidewall, produced toward the inside of displacement; tunnel vertical stress focused on the tunnel vault and floor, a direction toward the inside of the tunnel, so that the tunnel vault produce subsidence, uplift the floor. Construction should be strengthened to support these areas.(4) By segments surrounding convergence and vault subsidence monitoring in Yushan tunnel through fault fracture zone, no large deformation occurs. The results found that compared with the numerical results reflect the project can approximate the actual results, but because of the complex geological site conditions, simplifying the model chosen, and tunnel-related parameters can not really the same as the actual tunnel simulation results relative to the actual monitoring results have certain bias. But the surrounding displacement trends and monitor the tunnel numerical measurement results obtained close, it can provide a reference for the modification fault fracture zone treatment program.