三车道大断面公路隧道软弱围岩施工技术

Construction Technology for Three-Lane Highway Tunnels with Large Cross-Sections Located in Soft Ground

重庆外环玉峰山隧道施工时遭遇了煤窑采空区、大溶洞、松散围岩堆积区、富水段,施工中采取了三台阶预留核心土、CRD工法、单侧壁导坑法和双侧壁导坑法实现了安全通过。结合玉峰山隧道的工程实际,介绍了隧道通过大溶洞充填区和松散围岩堆积区所采用的开挖方法和辅助施工方法,总结了一些三车道大断面公路隧道软弱围岩的施工技术,以期能对类似工程有一定的借鉴作用。

Coal mine goafs,large karst caves,loose debris ground and rich water are encountered during the construction of Yufengshan tunnel on Outer Ring Road of Chongqing.'Top heading and bench' method with preserved core soil,CRD method,single side drift method and double side drift method are used in the tunnel construction and safe construction is ensured.Taking the construction of Yufengshan tunnel as an example,the author presents the excavation method and assistant construction methods for tunneling through the filling area of large karst caves and loose debris ground and summarizes the construction technology for three-lane highway tunnels with large cross-sections located in soft ground,hoping to provide reference for similar projects in the future.