【摘要】 针对综放剧烈采动影响煤巷窄煤柱出现的破裂失稳问题,采用理论分析、数值模拟和现场实测等相结合的研究方法,探讨窄煤柱破裂失稳机理及其控制技术。结果表明:1)受上覆岩层破断回转运动影响,窄煤柱帮发生明显水平挤压运动,造成浅部煤体挤压、错动和破碎,变形破坏主要发生在煤柱帮中上部区域;2)关键块回转运动行为将对沿空巷道围岩产生沿铅垂方向的支承压力σj,同时还将对窄煤柱产生水平力σ_d,在此复杂应力作用下沿空巷道窄煤柱发生破裂失稳,由浅至深煤体应变演化过程为拉应变→压应变→拉应变;3)阐明该类巷道控制原理,提出"高强锚杆支护+顶板锚索槽钢组合结构+煤柱帮锚索加固"的综放沿空巷道支护方案并进行现场应用。现场工程实践表明,该技术可有效控制综放沿空巷道围岩变形。更多还原

【Abstract】 In view of the fracture and instability of a narrow pillar in a gob-side entry in fully mechanized caving mining under intense mining, a comprehensive method including theory analysis, numerical modeling and field monitoring has been employed to study its fracture and instability mechanism and control technology. The results have indicated that:1) Under the effect induced by fracture and rotation movement of unstable overlying strata, the obvious squeezing movement occurred in the coal mass of a narrow pillar, resulting in squeezing, dislocating, and fracturing in the coal mass, and the main deformation and failure zone is in the middle and upper zone of the coal pillar. 2) A mining stress in the vertical direction σj induced by the rotation movement of the key blocks will be exerted on the coal masse surrounding the gob side entry, meanwhile a compression stress in the horizontal direction σd will be exerted on the coal pillar. Consequently, under the effect of this compound stress, squeezing and fracture and instability occurred in the narrow coal pillar in the gob side entry; the evolution process of the strain from the shallow to deep in the coal mass was tension strain-compression strain-tension strain. 3) The control mechanism of the entry has been proposed, and a support scheme including "high strength bolts support + cables and steel combined structure in the roof + cables in the coal pillar" has been employed in the field. The field engineering practice indicates that this support technology can control the deformation of the coal mass surrounding the gob side entry effectively.更多还原