深部远距离下保护层开采多关键层运移—裂隙演化—瓦斯涌出动态规律研究  

Rule of multi-key strata movement-fracture evolution-dynamics of gas emission in deep long distance lower protective layer mining

作　　者：杨科[1] 刘帅[1,2] YANG Ke;LIU Shuai(State Province Key Laboratory of Mining Resp onsc and Disaster Prevention and Control in Deep Coal Mine,Anhui University of Science and Technology,Huainan,Anhui 232001,China;School of Resources and Civil Engineering,Northeastern University,Shenyang,Liaoning 110819,China)

机构地区：[1]安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室,安徽淮南232001 [2]东北大学资源与土木工程学院,辽宁沈阳110819

出　　处：《采矿与安全工程学报》2020年第5期991-1000,共10页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金重点项目(51634007);安徽省115创新团队项目。

摘　　要：为了探索淮南矿区深部A组煤开采远距离上行卸压B组煤的可行性,以潘二矿A3煤11223工作面及B4煤为工程背景,采用理论分析、实验室测试、相似模拟试验以及现场观测的手段,研究了覆岩不同关键层结构远距离下保护层开采采动裂隙动态演化规律和卸压特征,以及多关键层运移对被保护层卸压瓦斯涌出动态的影响。研究表明:1)沿工作面走向采动裂隙随关键层破断"跳跃式"向上扩展,岩层稳定后采空区中部裂隙被重新压实,切眼、工作面侧裂隙由于煤柱作用长期存在,共同构成"梯形裂隙区"。关键层竖向破断裂隙未贯通时,其随动岩层不会形成离层裂隙,同时对穿层裂隙的扩展也起到阻隔作用,致使保护层卸压角减小;2)沿工作面倾向裂隙分布为整体偏向上山方向的"斜梯形",倾向上部裂隙较发育。控制被保护层运移的关键层破断裂隙未贯通时,被保护层卸压系数和卸压范围均有所减小;3)由于11223工作面东一段和西二段覆岩关键层结构不同,导水裂隙发育高度存在显著差异,被保护层B4煤东、西两段煤层透气性系数分别扩大了592倍和105倍,从增透倍数和瓦斯抽采量来看,潘二矿下保护层A3煤11223工作面开采卸压B4煤是可行的,且东一段卸压效果明显优于西二段;4)由瓦斯抽采数据反演获得的各关键层破断步距与相似模拟试验结果有较好一致性,关键层的运移对被保护层瓦斯涌出动态起控制作用。In order to explore the feasibility of deep coal seam group A with upward far distance pressure-relief in coal seam group B in Huainan mining area, with working face 11223 in the coal seam A3 and coal seam B4 of Pan No. 2 coalmine as engineering background, the dynamic evolution law of mining-induced fractures and pressure-relief characteristics in different overlying key strata structures under far distance lower protective layer mining as well as the effect of multi-key stratum migration on the gas emission from protective layer have been studied through theoretical analysis, laboratory experiment, similar material simulation test and field measurements. Research results have shown that 1) Along the strike of panel, mining-induced fracture increases in saltatory manner with the key stratum breaking and after the rock formation is stabilized, the cracks in the middle part of the goaf are re-compacted. The fractures in the cutting hole and working face due to the action of coal pillars for a long time, jointly form a "trapezoidal fracture area". When the vertical fracture of the key layer is not connected, a separation fracture in the following rock layer cannot be formed and the expansion of trans-layer cracks can be blocked, which decreases the pressure relief angle of the protective layer;2) Inclined fissures along the working face are distributed as an "inclined trapezoid" in the uphill direction as a whole, with more developed fissures on the upper side. When the breaking fracture of key stratum that controls the migration of the protected layer is not connected, the pressure-relief coefficient and scope of protected layer decrease;3) Because of the different key stratum structures of the eastern 1 st and western 2 nd section overlying the panel 11223, there is a significant difference in the development height of the water flowing fracture and the permeability coefficients of the eastern and western sections of the protective coal seam B4 are expanded by 592 times and 105 times respectively. According to th

关 键 词：下保护层开采 相似模拟试验 关键层运移 裂隙演化 瓦斯涌出动态 

分 类 号：TD353[矿业工程—矿井建设]