Abstract:

During the construction of New Shuhe tunnel on the second XiangfanChongqing railway, serious deformation occurs after tunnel excavation, which results in the interference of the primary support. In the paper, the construction technologies for tunnels located in soft rock mass with serious deformation potentials are summarized, and case study is made on the construction of New Shuhe tunnel, by means of numerical simulation and construction verification, in terms of “top heading + two benches” method, “top heading + temporary invert” method and “Bench I + temporary invert” method. The study shows that the “Bench I + temporary invert” method is the best solution for the tunnel. “Bench I + temporary invert” method has been adopted for the tunnel, the serious deformation of the tunnel has been brought under control, the construction cost has been reduced, the construction efficiency has been improved and the construction risks have been minimized.

Key words: New Shuhe tunnel, soft rock, serious deformation, “top heading + two benches&rdquo, method, “top heading + temporary invert&rdquo, method, “Bench I + temporary invert&rdquo, method, monitoring