翁明月,苏士杰,孙如达,等. 多关键层窄煤柱冲击地压发生机理与三级协同防治技术[J]. 煤炭学报,2024,49(S1):45−56. DOI: 10.13225/j.cnki.jccs.2023.0478
引用本文: 翁明月,苏士杰,孙如达,等. 多关键层窄煤柱冲击地压发生机理与三级协同防治技术[J]. 煤炭学报,2024,49(S1):45−56. DOI: 10.13225/j.cnki.jccs.2023.0478
WENG Mingyue,SU Shijie,SUN Ruda,et al. Research on rock burst generation mechanism and three-level collaborative control technology of multi-key strata narrow coal pillar[J]. Journal of China Coal Society,2024,49(S1):45−56. DOI: 10.13225/j.cnki.jccs.2023.0478
Citation: WENG Mingyue,SU Shijie,SUN Ruda,et al. Research on rock burst generation mechanism and three-level collaborative control technology of multi-key strata narrow coal pillar[J]. Journal of China Coal Society,2024,49(S1):45−56. DOI: 10.13225/j.cnki.jccs.2023.0478

多关键层窄煤柱冲击地压发生机理与三级协同防治技术

Research on rock burst generation mechanism and three-level collaborative control technology of multi-key strata narrow coal pillar

  • 摘要: 以门克庆煤矿11–3106工作面为背景,建立了11–3106工作面上覆厚硬覆岩结构破断模型,研究了深部厚硬顶板高强度开采条件下多关键层窄煤柱临空巷道冲击地压发生机理,提出了“钻−爆−压”三级协同卸压防治技术并现场应用,采用震波CT技术、微震监测、支架压力监测和地表沉降观测等多种手段进行了卸压效果验证。研究结果表明:11–3106工作面上覆存在高、低位关键层,当两关键层破断时,均可能造成覆岩大范围运动,临空巷道围岩受动载扰动影响大;窄煤柱承载能力低,使得覆岩载荷向巷道实体煤侧传递,实体煤侧应力增高,是冲击启动的主要区域;在侧向固定支承压力和本工作面移动支承压力叠加作用下,实体煤侧应力集中程度不断升高,受坚硬顶板周期性破断影响,“动静”加载容易诱发临空巷道冲击显现;坚硬顶板既是11–3106工作面系统内高静载力源,又是系统外强动载荷来源。对于11–3106工作面的冲击地压防治,应同时从3个方面入手:① 弱化煤体,形成冲击发生的缓冲隔离带;② 预裂低位顶板,减弱煤岩体致密程度,破坏系统内外的蓄能条件;③ 预裂高位顶板,人为诱发中高位关键层破断。开发了“钻−爆−压”三级协同卸压防治技术,现场实施后,降低了高、低位厚硬顶板破断带来的冲击动载,减弱了煤体内高应力区的应力集中程度,高能量微震事件大幅减少,降低了工作面回采期间的围岩活动性,工作面顶板来压强度降低,地面沉降值增加200%,表明“钻−爆−压”三级协同卸压具有良好的“释能减冲”效果,可为类似厚硬顶板条件下窄煤柱工作面的冲击地压防治提供借鉴。

     

    Abstract: Taking the 11–3106 working face of Menkeqing Coal Mine as the research background, a fracture model of the structure covered by thick and hard overburden at the 11–3106 working face was established. The mechanism of rock burst in the open roadway of narrow coal pillar with multiple key layers under the deep thick and hard roof mining condition with high strength was studied. The three-level collaborative pressure relief prevention technology of “drilling, blasting and pressuring” was proposed and applied in the field. Seismic CT, microseismic monitoring, support pressure monitoring and surface subsidence observation were used to verify the effect of pressure relief. The results show that there are high and low key layers overlying the working surface of 11–3106. When the two key layers break, the overlying rock may move in a wide range, and the surrounding rock of the open roadway is greatly affected by the dynamic load disturbance. The low bearing capacity of the narrow coal pillar makes the overburden load transfer to the solid coal side of the roadway and the stress increase on the solid coal side, which is the main area of impact initiation. Under the superposition of the lateral fixed abutment pressure and the mobile abutment pressure of the working face, the stress concentration degree of the solid coal side increases continuously. Affected by the periodic breaking of the hard roof, the “dynamic and static” loading is easy to induce the impact of the open roadway. Hard roof is not only the high static load source in the 11–3106 working face system, but also the source of strong dynamic load outside the system. For the prevention of rock burst at the 11–3106 working face, the measures should be taken from three aspects at the same time: ① the coal body is weakened to form a buffer and isolation zone for impact; ② the low pre-cracking roof is weakened to reduce the density of coal rock mass and destroy the energy storage conditions inside and outside the system; and ③ the high pre-cracking roof is artificially induced to break the key layer in the middle and high levels. The three-level collaborative pressure relief prevention and control technology of “drilling, blasting and pressuring” was developed. After the on-site implementation, the impact dynamic load caused by the breaking of high and low thick hard roof was reduced, the stress concentration in the high stress zone in the coal body was weakened, the high energy microseismic events were significantly reduced, the surrounding rock activity during the mining of working face was reduced, the compressive strength of working face roof was reduced, and the ground settlement value was increased by 200%. The results show that the three-stage coordinated pressure relief of “drilling, blasting and pressuring” has a good effect of “energy release and impact reduction”, which can provide a reference for the rock burst prevention and control of narrow coal pillar working face under similar thick hard roof conditions.

     

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