• 中文核心期刊
  • 中国科技核心期刊
  • RCCSE中国核心学术期刊
  • Scopus, DOAJ, CA, AJ, JST收录期刊
高级检索

近距离煤层群切顶留巷覆岩应力及变形响应研究

Study on strata stress and deformation response of contiguous seams under cutting roof for entry retaining

  • 摘要: 为了深入了解近距离煤层群切顶留巷上覆岩层应力及变形演化规律,以白皎煤矿B4煤层、B3煤层、B2煤层切顶成巷巷道2442、2443及2444运输平巷为研究对象,开展了3层煤回采巷道开挖物理试验研究,结果表明:①上煤层巷道切顶后,顶板卸压; 煤层开挖后,采空区顶板垮落并支撑巷道顶板,顶板增压; 煤层继续开挖,覆岩断裂,顶板卸压; 巷道顶板应力依次经历卸压、增压及卸压过程,其中,高位顶板应力增加较大,应力较高。②中部巷道切顶及煤层开挖后,上覆岩层压力同时向上煤层巷道围岩及本巷道采动破碎压实围岩转移,并在两巷道之间的上覆岩层中形成应力增高区。③下煤层巷道切顶及煤层开挖后,巷道围岩破坏严重,无集中应力,受前两次开挖卸压影响较大。④上覆岩层沿层理面出现错动变形,同时出现垂直拉伸剪切裂纹,采动影响越大,裂纹扩展程度越大。

     

    Abstract: In order to deeply understand the deformation evolution law of overburden stress of contiguous seams under cutting roof for entry retaining, taking the transportation drift 2442, 2443 and 2444 in B4 coal seam, B3 coal seam and B2 coal seam of Baijiao Coal Mine as the research object, the excavation physical test of 3 coal seams was carried out, the results show that: ①after cutting the roof of roadway in upper coal seam, the roof is relieved; after coal excavation, the goaf roof caves and supports the roadway roof, leading to roof pressurizing; with the further excavation of coal seam, the overburden fractures, the roof pressure is relieved again; the roof stress of roadway goes through the process of pressure relief, pressure increase and pressure relief successively, among which, the stress of upper roof increases greatly and the stress is higher.②After cutting the roof of the central roadway and coal seam excavation, the pressure of overburden is transferred to the surrounding rock of the upper coal seam roadway and the subsidence crushed and compacted surrounding rock of the roadway, the stress-concentrated area is formed in the overburden between the two roadways. ③The surrounding rock is seriously damaged and without concentrated stress after roof cutting of the lower roadway and coal seam excavation, which are greatly affected by the pressure relief of the first two excavations. ④Dislocation deformation and vertical tensile shear cracks appeares along the roof rock mass, and the greater the subsidence influence, the greater the crack propagation degree.

     

/

返回文章
返回