锚杆加固恩施大峡谷绝壁危岩的稳定性数值分析

Numerical Analysis of the Stability of the Dangerous Rock Strengthened by Bolt in Enshi Grand Canyon

以恩施大峡谷绝壁陡崖的锚杆危岩治理工程为例,采用有限元数值模拟的方法研究了降雨前后危岩以及不同锚杆的长度、入射角、数量、间距参数选择对危岩受力及变形情况,并综合评判其稳定性。结果表明:采用单根锚杆时,在锚杆超过推测滑动面后不受长度变化影响,而锚杆入射角越小,对其控制效果越好;在同一剖面上采用2根锚杆、锚杆间距为2.5 m时控制效果最好;在同一剖面上采用3根锚杆、锚杆间距为3.5 m和4.5 m时其控制效果基本一致;同一剖面上位置偏下的锚杆受应力更大,因而应加大下部位置锚杆承受应力的能力。

The anchor bolt on the steep cliffs of Enshi grand canyon was taken as an example to develop the finite element numerical simulation method which is then used to calculate the parameters of the dangerous rocks before and after the rainfall and the different length of anchor bolt, angle of incidence, the quantity and the spacing influence stress and deformation of dangerous rocks, and then comprehensively evaluate its stability. The results show that when single anchor bolt is used, it is not affected by the length change after exceeding the expected slip surface;when two anchor bolts are used in the same section, the control effect is best when the spacing is 2.5 m;when three anchor bolts are used in the same section, the control effect is basically the same when spacing is 3.5 m and 4.5 m. the lower anchor bolt in the same section is more stressed, so the lower one should be able to bear the stress better in actual engineering.