摘要
高应力环境临空小煤柱巷道面临围岩稳定性差,巷道维护难度大等问题,以福达煤矿15#煤层5 m小煤柱应用现场为背景,针对影响小煤柱巷道围岩稳定性的关键因素,包括:地应力水平高、围岩稳定性差、煤柱内部遗留钻场空区等,提出了侧向水力压裂卸压、临空巷道围岩稳定性控制及煤柱内隐蔽钻场高水材料充填技术方案,并开展现场应用,结果表明:(1)水力压裂关键层位起裂压力峰值为26.5 MPa,各孔最大压力均值22.3 MPa,孔内原生裂隙受高压水挤压作用逐渐张开,对顶板完整性的弱化作用显著;(2)基于巷道矿压数据分析结论,顶板锚杆应力峰值为108 kN,帮锚杆应力峰值为86 kN,均远低于锚杆的屈服载荷,未出现断锚现象。巷道两帮及顶板下沉量均在可控范围内,巷道收缩量较小,围岩整体稳定性得到有效控制;(3)隐蔽钻场充填高水材料总体积682.9 m3,高于钻场空区总体积,每个充填钻孔均保证返浆后停止注浆,钻场充满率较高,残留1.5 m煤柱稳定性较好,达到了预期效果。
The small coal pillar roadway in the high stress environment is facing the problems of poor stability of surrounding rock and difficult maintenance of roadway.Taking the application site of 5 m small coal pillar in 15#coal seam of Fuda Coal mine as the background,aiming at the key factors affecting the stability of surrounding rock of small coal pillar roadway,including high in-situ stress level,poor stability of surrounding rock and drilling field goaf left in coal pillar,the technical scheme of lateral hydraulic fracturing pressure relief,stability control of surrounding rock of empty roadway and high water material filling in hidden drilling field in coal pillar is put forward,and field application is carried out.The results show that:(1)The peak initiation pressure of the key layers of hydraulic fracturing is 26.5 MPa,and the average maximum pressure of each hole is 22.3 MPa.The primary cracks in the hole are gradually opened by the extrusion of high-pressure water,which weakens the integrity of the roof significantly.(2)Based on the analysis of roadway mine pressure data,the peak stress of roof bolt is 108 kN,and the peak stress of side bolt is 86 kN,which are far lower than the yield load of bolt,and there is no anchor breaking phenomenon.The subsidence of the two sides and roof of the roadway is within the controllable range,the shrinkage of the roadway is small,and the overall stability of the surrounding rock is effectively controlled.(3)The total volume of filling high-water materials in the hidden drilling field is 682.9 m^(3),which is higher than the total volume of the empty area of the drilling field.Each filling borehole ensures that the grouting is stopped after the slurry is returned.The filling rate of the drilling field is high,and the stability of the residual 1.5 m coal pillar is good.
作者
于健浩
刘鹏亮
崔锋
YU Jianhao;LIU Pengliang;CUI Feng(CCTEG Coal Mining Research Institute,Beijing 100014,China;Tiandi Science and Technology Co.,Ltd.,Beijing 100013,China)
出处
《煤炭工程》
北大核心
2023年第12期71-77,共7页
Coal Engineering
关键词
高应力煤体
小煤柱护巷
水力压裂
围岩稳定性
钻场充填
high stress coal mass
small coal pillar support lane
hydraulic fracturing
stability of surrounding rock
drilling field filling
