摘要
常规大直径卸压钻孔对巷道浅部围岩扰动较大,增加了支护成本。以变直径卸压钻孔为研究对象,采用理论分析、数值模拟的方法,分析了变直径卸压钻孔卸压机理,讨论了变直径钻孔损伤形状、卸压半径、钻孔布置方式和钻孔长度等因素,同时比较了不同钻孔方案的优劣。结果表明:变直径钻孔在围岩浅部使用小直径钻孔,可以减小浅部围岩变形,对浅部围岩扰动更小,在煤层深部采用大直径,可以为煤体提供更大的能量释放空间,卸压效果好;在垂直应力大于水平应力的情况下,钻孔损伤为“蝴蝶”型,因此采用双排三花布置效果最佳;小直径段长度不超过应力降低区,其长度为3 m,其总长度不超过应力集中区,为25 m;变直径卸压钻孔可以在有效卸压的同时减小对巷道浅部围岩的扰动。
Conventional pressure-relief drlling with large diameters causes significant disturbance to shallow surrounding rocks in tunnels,leading to increased support costs.This study focuses on the variable-diameter pressure-relief drilling method and uses theoretical analysis and numerical simulation methods to analyze its pressure-relief mechanism,drlling damage shape,pressurerelief radius,drilling layout,drilling length,and other factors,while comparing the advantages and disadvantages of different drlling schemes.The results show that the use of small-diameter drilling in shallow surrounding rocks can reduce deformation and disturbance,while large-diameter drilling in deep coal seams can provide more space for energy release and achieve better pressure-relief effect.When the vertical stress is greater than the horizontal stress,the drilling damage is in a"butterfly"shape;therefore,the use of double-row three-flower arrangement has the best effect.The length of the small-diameter segment should not exceed the original stress,which is 3 m,and the total length should not exceed the stress concentration zone,which is 25 m.The variable-diameter pressure-relief drlling method can effectively reduce disturbance to shallow surrounding rocks and achieve pressure relief.
作者
谢军
李刚
姜安琪
XIE Jun;LI Gang;JIANG Anqi(College of Safety and Environmental Engineering,Shandong University of Science and Technology,Qingdao 266590,China)
出处
《煤矿安全》
CAS
北大核心
2023年第7期85-92,共8页
Safety in Coal Mines
关键词
变直径
卸压钻孔
冲击地压防治
蝶型破坏
数值模拟
variable-diameter
pressure-relief drilling
rock burst prevention
butterfly failure
numerical simulation
