锁脚锚杆和系统锚杆对软弱围岩隧道安全性影响研究

针对软弱围岩隧道开挖过程中,出现变形过大的问题,施工现场往往采用锁脚锚杆和系统锚杆的支护措施.通过数值模拟的方法,对比分析锁脚锚杆和系统锚杆对支护结构的变形和内力的影响,得到如下结论：锁脚锚杆在隧道整体下沉方面,作用更为明显;系统锚杆对隧道的水平收敛效果更好;添加系统锚杆相对于锁脚锚杆对隧道整体的安全性提高更大.综合考虑软弱围岩拱顶沉降大和水平收敛大的现状,施工过程中,应该综合使用系统锚杆和锁脚锚杆,以保证隧道的安全施工.

Study on system security of lock foot bolt and anchor of weak rock tunnel

In view of the weak rock tunnel excavation process, the problems of large deformation, and the con- struction site tend to lock the foot bolt and the system of anchor supporting measures. By using the method of numerical simulation analysis of lock foot bolt and anchor system influence on the deformation and internal force of retaining structure, we get the following conclusion： effect is more obvious for lock foot bolt in terms of overall tunnel subsidence; System anchoring bolt on the level of the tunnel convergence effect is better; add system anchoring bolt, compared with lock foot bolt, is more safe for the tunnel. Considering the current situa- tion of the vault subsidence and horizontal convergence of weak surrounding rock, in the construction process, integrated system using anchor bolt and lock foot should be considered to ensure the safety of tunnel construction.