公路隧道初期支护大变形处理

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松弛的主要支护手段，而二次衬砌是在围岩与初期支护变形基本稳定的情况下修筑的，初期支护是二次衬砌的基础，初期支护大变形的预防与整治成为破碎松散地质条件下隧道施工的关键，针对初期支护大变形的危害，分析了龙眼睛隧道初期支护大幅变形的原因，提出了初期支护大变形的整治的措施。

The Processing for Large-scale Deformation of Early Support in Road Tunnel

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 main means controlling 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 have become the key to he excavation of soft surrounding rock tunnels. In the light of the harms in large-scale deformation of early support, this paper analyzes the cause of large-scale deformation of early support in Lingyanjing tunnel. The measures for renovation of large-scale deformation of early support are presented.