摘要
针对极近距离煤层渐变层间距下伏巷道层间顶板厚度较小且波动变化较大的特殊赋存条件,下伏巷道面临着单一支护方案难以适应渐变层间顶板极易破碎、围岩变形量大等难题,以泰山隆安煤矿11下309工作面回风巷的1~7 m渐变层间顶板为研究背景,采用理论分析、数值模拟手段对极近距离条件下采空区煤柱底板三维应力分布规律进行研究,对比分析下伏巷道层间顶板厚度变化对巷道围岩变形规律及破坏特征的差异性,揭示极近距离下伏巷道渐变层间顶板厚度变化与巷道围岩破坏的内在联系,提出了极近距离渐变层间距下伏煤层巷道围岩分区域支护控制技术。研究结果表明,基于极近距离采空区的遗留煤柱底板三维应力衰减演化规律,当层间距较小时下伏巷道围岩的垂直应力、水平应力扰动对巷道围岩变形影响严重;通过数值模拟研究不同错距及层间距厚度变化因素对下伏巷道围岩破坏形态及变形规律的差异性,构建了下伏巷道围岩水平应力、垂直应力、变形规律及破坏形态评价指标,对巷道围岩破坏形态进行分类,得出了极近距离渐变层间距下伏巷道围岩破坏变形的临界层间距为3 m;基于巷道顶板厚度变化提出了渐变层间顶板厚度<3 m和>3 m工况条件下的分区域支护设计,结合现场分区域支护效果得出回风巷变形较小,验证了临界层间3 m条件下的分区域方案的可行性。
In view of the special occurrence condition of extreme close distance coal seams with gradient layer spacing,where the interlayer roof thickness above underlying roadways exhibits significant fluctuations and minimal dimensions,underlying roadways face engineering challenges where conventional single support schemes prove inadequate to address gradient interlayer roof thickness variations,frequently resulting in roof fragmentation and excessive surrounding rock deformation.Focusing on the 1–7 m gradient interlayer roof of the air return roadway in working face 309 of the lower No.11 coal seam at Taishan Long'an Coal Mine,this study investigates the three-dimensional stress distribution characteristics of residual coal pillar floors in goaf areas under extreme close distance conditions through theoretical analysis and numerical simulation.A comparative analysis was conducted to evaluate the differential impacts of interlayer roof thickness variations of underlying roadway on deformation patterns and failure characteristics of roadway surrounding rocks.The intrinsic relationship between gradient interlayer roof thickness and surrounding rock failure mechanisms in extreme close distance underlying roadways was revealed,leading to the proposal of a zonal support control technology tailored to gradient layer spacing conditions.The research results indicate that based on the stress attenuation evolution law of three-dimensional distribution characteristics of residual coal pillar floors in goaf areas under extreme close distance conditions,reduced layer spacing exacerbates vertical and horizontal stress disturbances,significantly aggravating roadway deformation;through numerical simulation of factors including different staggered distances and layer spacing thickness variations,this study investigates their differential impacts on failure patterns and deformation characteristics of underlying roadway surrounding rocks.Evaluation indices for horizontal stress,vertical stress,deformation patterns,and failure morphology are established to classify surrounding rock damage,identifying 3 m as the critical layer spacing threshold for failure deformation in extreme close distance roadways with gradient layer spacing.Based on the variation of the thickness of the roadway roof,a zoning support design is proposed for the gradient interlayer roof under different thickness conditions of less than 3 m and more than 3 m.Combined with the on-site zoning support effect,it is found that the deformation of the return roadway is relatively small,verifying the feasibility of the zoning scheme under the critical interlayer 3 m condition.
作者
张钢举
梁冰
ZHANG Gangju;LIANG Bing(Datong Company of Jinneng Holding Group Co.,Ltd.,Datong,Shanxi 037000,China;College of Mining,Liaoning Technical University,Fuxin,Liaoning 123000,China)
出处
《中国煤炭》
北大核心
2025年第4期86-97,共12页
China Coal
关键词
极近距离煤层
渐变层间距
巷道围岩控制
底板破坏深度
支护技术
extreme close distance coal seam
gradient layer spacing
underlying roadway
roadway surrounding rock control
floor failure depth
support technology
作者简介
张钢举(1976-),男,陕西渭南人,硕士研究生,高级工程师,主要从事煤矿开采技术研究工作。E-mail:1471112609@qq.com。
