南坪隧道不良地质段地表加固施工技术

Surface Reinforcement Construction Technology for Adverse Geological Segment of Nanping Tunnel

南坪隧道出口不良地质段位于相对较深的冲沟内,隧道内围岩为软流塑状Ⅵ级围岩,在施工中采用地表旋喷桩深孔注浆的方法,起到了抗滑移和防渗透作用,使之增强了岩体的整体性和覆盖层土体抗剪破坏的能力,有效的控制了地表的沉陷,大大的改良了围岩状态。

The adverse geological segment of Nanping tunnel exit is located in a relatively deep rushing gully. The surrounding rock in the tunnel is grade-VI soft current-formed surrounding rock. The method of deep hole grouting by the surface rotary jet grouting pile is adopted to resist slippage and prevent leaking, so as to improve the wholeness of rock and the ability of anti-shear failure of covering layers, which will efficiently control the surface subsidence and greatly improve the state of surrounding rock.