公路隧道初期支护大幅变形的防治

The Prevention and renovation for Large-scale Deformation of Early Support in Road Tunnels

初期支护是新奥法的主要承载结构,它是密贴于围岩的柔性结构与控制围岩变形的松弛,而二次衬砌是在围岩与初期支护变形基本稳定条件下修筑的,初期支护是二次初砌的基础,初期支护大量变形的整治和预防成为软弱围岩隧道掘进的关键。文章针对初期支护大幅变形的危害,分析了芙蓉山隧道钢架加锚喷初期支护大幅变形的原因,提出了初期支护大幅变形成功的整治和预防的方法。

Early support is the main loadbearing structure in NATM (New Austrian Tunneling Method). It is a flexible structure closely attached to the surrounding rocks and controls the looseness of the rock deformation. The second lining is established when the deformation of surrounding rocks and early support has been basically stabilized. As early support is the foundation of the second lining, the prevention and renovation for large scale deformation of early support has become the key to the excavation of surrounding soft rock tunnels. In light of the hams in largescale deformation of early support, this paper analyzes the cause of largescale deformation of early support with steel scaffold and anchor in Furongshan Tunnel. It presents the successful approaches for prevention and renovation of largescale deformation of early support.