煤矿深部开采冲击地压监测解危关键技术研究

Key technology of rock burst monitoring and control in deep coal mining

针对煤矿深部开采冲击地压监测防治难题,采用理论分析、数值模拟、室内试验和现场监测相结合的综合研究方法,研究了深部应变型、断层滑移型和坚硬顶板型3类冲击地压的致灾机理,提出了煤岩组合冲击能速度指数和卸围压冲击能速度指数两个新指标,建立了与冲击地压类型相适应的煤岩冲击倾向性评价体系,获得了深部开采3类冲击地压的前兆信息特征,给出了以深部开采冲击地压类型为导向的监测预警及组合式卸压解危方法,研发了钻孔施工与预警同步一体化技术。结果表明:(1)深部应变型冲击地压是围岩系统能量积聚大于能量释放与耗散之和的结果;与浅部开采相比,深部坚硬顶板破断释放的变形能明显增大,以及深部断层更易发生错动滑移;(2)深部应变型和深部坚硬顶板型冲击地压的冲击倾向性评价需在国家标准基础上分别增加卸围压冲击能速度指数、煤岩组合冲击能速度指数,而对于深部断层滑移型冲击地压,这两个指标均需增加;(3)深部应变型和深部坚硬顶板型冲击地压监测预警应以能量和应力判据为主,但深部断层滑移型冲击地压应以能量判据为主;(4)深部应变型冲击地压解危方法优先顺序为开采保护层、大直径钻孔、断底和煤层注水;深部坚硬顶板型冲击地压解危方法优先顺序为开采保护层、深孔断顶爆破、大直径钻孔、断底和煤层注水;深部断层型冲击地压解危方法优先顺序为开采保护层、大直径钻孔和煤层注水;(5)采用钻孔施工与预警同步一体化技术,可在钻孔施工过程中通过监测煤粉量和应力变化信息,对施工过程中可能发生的冲击危险进行同步预警。煤矿深部开采冲击地压防治作为一个复杂的系统工程,以科学分类为基础的系统防治技术体系仍是深部开采冲击地压需要重点攻关的研究方向。

Rock burst mitigation and monitoring is a challenge during deep coal mining.Theoretical analysis,numerical simulation, laboratory tests and field monitoring are all used for researching this issue.First, the occurrence mechanisms of three types of rock burst ( i.e., strain rock burst, fault slip rock burst and hard roof rock burst) are researched.Second, two new burst liability indexes are proposed to improve the evaluation system of burst liability,which makes the burst liability evaluation system more suitable for deep coal mining.Third, the precursor information characteristics of the three rock burst types are given.Forth, the corresponding monitoring-warning and combined pressure relief methods are proposed.At last, synchronization technique of drilling and monitoring is developed.Main conclusions are as follows: ① Deep strain rock burst is the result that the energy accumulation of surrounding rock system is larger than that of superposition of energy release and energy dissipation.Compared with shallow mining, the released energy of deep hard roof fracturing increases and deep fault slips more easily.② When evaluating burst liability of deep strain rock burst and hard roof rock burst,burst energy speed indexes of unloading confining pressure and combined coal-rock need to be added except the national standard, respectively.For deep fault slip rock burst, the two new indexes are all need to be added.③ Monitoring and warning of deep strain rock burst and deep hard rock burst should depend on energy and stress criteria,while for deep fault slip rock burst,energy criterion is the priority.④ Priorities for mitigating deep strain rock burst are protective seam mining, large-diameter drilling, floor fracturing and water infusion.Priorities for hard roof rock burst are protective seam mining, roof fracturing, large-diameter drilling, floor fracturing and water infusion.Priorities for fault slip rock burst are protective seam mining, large-diameter drilling and water infusion.⑤ When using the synchronization technique of drilling and monitoring,drilling powder and stress change can be monitored for potential burst warning during drilling process.System establishment of control technique based on scientific classification still will be the direction of future research.