Research On Numerical Simulation Of The Slope Stability Under Bias Of Double-arch Tunnel In The Sotf Surrounding Rock

When constructing senior highways in China, the project of double-arch tunnel is often adopted in special geologic and limited topography districts in order to meet the need of road type and outspreading road, to get better technological and economical purpose. At present considerable amount double-arch tunnels have been constructed in our country. But there are many problems in the construction and mobilization of the double-arch tunnels such as double-arch tunnel construction in soft soil, slope residual body, such as landslide on soft ground, as at the end of the foundation bearing capacity, poor stability, double-arch tunnel construction and operation of the disease may occur in more and more difficult to build. Papers move to Ning River Highway back on the 4th double-arch tunnel project as background, the construction process through the plane of its elastic-plastic finite element analysis and monitoring on-site measurement data processing, discussed the double-arch tunnel bias circumstances surrounding the construction process and the slope of the stress field, displacement field, as well as the supporting structure in the wall of the distribution of the stress field. Papers obtained:(1) Strengthening measures to meet the basic engineering requirements. Jet Grouting through the basement to the basement after reinforcement, eliminating the guide hole in the bottom that may arise through the plastic zone, to ensure construction safety has played a decisive role. Anti-slide pile and pile consisting of elected strengthening system can be integrated to ensure that the slope does not slip, and better suppression of the top wall and vertical surface settlement can be a significant reduction in the initial stage of the supporting structure stress, significantly increased the safety factor of the tunnel.(2) anti-slide pile in the project played a major supporting role and security of reserves. Through the front slope of the analysis can be seen integrated in the natural conditions of stability, in the tunnel above the Ministry of Construction to the destruction of the tunnel clearance slump rather than the occurrence of landslide. Can also be seen by calculating the stress level of anti-slide pile has always been maintained at a lower level. (3) reinforces the measure not carries on reinforcement processing in view of the right flank main hole in the accumulative stratum and the strong regolith contact surface spot, existence certain flaw. In the construction process, has the disadvantage factor slightly, right flank still had the possibility to cause the plastic area extends to the slope body above either along the contact surface, causes the hole to go against collapsing or collapses slippery along the contact surface.