水平主应力下矿山巷道围岩稳定性分析

Stability analysis on the influence of horizontal principal stress on roadway surrounding rock

在数值模拟的基础上,结合武钢某铁矿阶段大巷工程实例,对巷道轴向与水平主应力呈不同方向时分别进行了模拟,分析了开挖后巷道围岩应力、位移变化规律以及塑性区的分布情况,并提出相应的支护方案。研究结果表明:在最大水平主应力的大小一定时,其方向是影响巷道围岩稳定性和支护设计的关键因素之一,最大水平主应力与巷道轴线的夹角越小越有利于巷道围岩的稳定;随着夹角的变大,顶板的应力和变形一直维持在较高的水平,两帮的受力和变形受到的影响较顶底板要大,支护时应该特别注意;喷锚支护可以改善围岩的塑性区,控制顶板沉降和两帮位移,确保巷道的安全。研究结果为采矿巷道稳定性分析和支护设计提供了重要的理论依据。

Based on numerical simulation, with the-large scale roadway project in one iron mine of Wuhan Steel Company as engineering background, separate experiments are conducted when the orientation of maximum horizontal principal stress is not consistent with the axial orientation of roadways. The post-excavation roadway surrounding rock stress, displacement and plastic zone distribution are analyzed and the corresponding supporting methods are proposed. The results show that when the maximum horizontal stress is constant,its direction is one of the key factors that influence the stability and supporting roadway design. The smaller the angle between the orientation of maximum horizontal principal stress and the axial orientation of roadway is, the more stable the roadway surrounding rock become; As the angle becomes larger, stress and strain on the roof will remain at a high level, which makes the both sides bear more stress and deformation, so it should be paid special attention to when supporting. Shotcrete and bolt supporting is a good alternative to improve the plastic zone and control roof subsidence and the displacement of both sides, ensuring safety of roadways. The study is of great importance to the stability analysis of roadway and the supporting scheme.