深井大断面软弱厚煤顶开切眼巷道围岩稳定性及控制

Stability and control of surrounding rock in open-cutting roadway of deep and large section of weak thick coal

针对深井大断面软弱厚煤顶切眼巷道存在的支护难题,以郭屯矿3301大采高工作面开切眼为工程背景,采用数值模拟、理论分析与现场实测相结合的方法,研究巷道围岩变形破坏规律及相应的控制技术,研究结果表明:①切眼巷道围岩依次划分为裂隙贯区、裂隙发育区、微裂隙区,随着切眼宽度增加,裂隙区位增大特征明显,当巷道宽度为12 m时,裂隙贯通区最大高度为2.6 m,两帮裂隙贯通区为1.1 m,顶板裂隙贯通区高度为1.5 m;②大断面、高采掘应力与煤体低强度是深井大断面厚煤顶切眼巷道稳定性主要影响因素,三者相互作用、相互影响,导致顶板和两帮裂隙快速发育进而发生塑性破坏,产生显著表面变形;③结合实际地质生产条件,提出了"高强锚杆支护+大直径锚索支护+单体柱加固"为核心的控制技术,并阐述了其控制机理,现场工业试验验证了支护方案的合理性。

In view of the support problems in the roadway of deep and thick section of deep mines, the open cut of the 3301 large mining face of Guotun Mine was taken as the engineering background, and the combination of numerical simulation,theoretical analysis and field measurement was adopted. The deformation and failure laws of surrounding rock and the corresponding control techniques were studied. The results showed that ① the surrounding rock of the cut-out roadway was divided into fractured zone, fractured zone and micro-fracture zone. With the increase of the width of the cut-eye, the location of the crack increased obviously, when the width of the roadway was 12 m, the maximum height of the fracture penetration zone was 2.6 m, the gap between the two fractures was 1.1 m, and the height of the fracture zone of the roof was1.5 m;② large sections, high mining stress and low strength of coal were the main influencing factors of the stability of the roadway in the deep section of thick coal with deep section, which caused the roof and the two sets of fissures developing rapidly and plastic deformation, resulting in significant surface deformation. ③ Combined with actual geological production conditions, "High-strength bolt support + large-diameter anchor cable support + single column reinforcement" was taken as the core control technology, and its control mechanism, on-site industry test verified the rationality of support programs.