深厚表土运动诱发高应力煤柱频繁冲击机制及防控试验研究  

Experimental study on mechanism and prevention of frequent impact of high stress coal pillars induced by deep topsoil movement

作　　者：张翔 朱斯陶 张修峰 王超 陈洋 李士栋 孔震 朱权洁[5] 袁腾飞 ZHANG Xiang;ZHU Sitao;ZHANG Xiufeng;WANG Chao;CHEN Yang;LI Shidong;KONG Zhen;ZHU Quanjie;YUAN Tengfei(School of Civil and Resource Engineering,Beijing University of Science and Technology,Beijing 100083,China;Shandong Energy Group Co.,Ltd.,Jinan,Shandong 250014,China;Coal Mine Rockburst Prevention and Control Research Center,Yanzhou Mining Group Co.,Ltd.,Zoucheng,Shandong 273500,China;Zhaolou Coal Mining Group Co.,Ltd.,Heze,Shandong 274705,China;School of Emergency Technology and Management,North China Institute of Science and Technology,Yanjiao,Hebei 065201,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083 [2]山东能源集团有限公司,山东济南250014 [3]兖矿集团有限公司煤矿冲击地压防治研究中心,山东邹城273500 [4]兖煤菏泽能化有限公司赵楼煤矿,山东菏泽274705 [5]华北科技学院应急技术与管理学院,河北燕郊065201

出　　处：《岩石力学与工程学报》2024年第10期2552-2569,共18页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点研发计划项目(2022YFC3004604);国家自然科学面上基金资助项目(52374076);中国科协青年人才托举工程项目(2021QNRC001)。

摘　　要：针对日益严峻的巨野煤田大巷煤柱冲击地压现状,以赵楼煤矿七采区大巷煤柱固定区域频繁冲击为工程背景,采用现场实测、数值模拟、理论分析和工业试验等方法,研究深厚表土运动诱发高应力煤柱频繁冲击机制,提出一种高应力孤立煤体弹核压裂防冲新方法,得到以下结论:采用PFC数值模拟发现厚表土随采场倾长的阶段性增长存在均布载荷、土压力拱、土拱与均载并存共3种加载模式,对应划分厚表土采场顺序接续条件下的地层运动阶段分别为基岩破断运动、岩土初次联动和岩土周期联动。通过研究断层阻隔与顺序接续条件下的厚表土地层载荷传递机制,设计了断层煤柱整体载荷分布曲线的量化方法,基于大巷切割影响的断层煤柱应力演化规律,建立孤立煤体应力分区承载工程模型,推导大巷孤立煤体群整体、局部失稳冲击工程判据。揭示深厚表土运动诱发高应力煤柱频繁冲击机制:由于岩土地层联动加载和大巷平行断层阻隔耦合影响,断层煤柱承载采场转移应力高度集中,同时大巷切割导致煤柱整体应力分散至孤立煤体群承载,当任一孤立煤体满足失稳冲击判据时,断层煤柱即频繁发生冲击显现。提出了一种高应力孤立煤体弹核压裂防冲方法,其原理为通过水力压裂降低弹性核区承载能力以促使孤立煤体整体载荷重新分布,实现其承载应力降峰均载的防冲目标,经工业试验发现弹性核区注水起裂压力约30 MPa,裂缝扩展长度与应力均化宽度大于21.2和14.5 m,现场监测表明弹核压裂能够减少孤立煤体应力集中程度,有效降低孤立煤体冲击危险水平。Facing the escalating rock burst risks in Juye coalfield's main coal pillars,and grounded in the frequent impacts at Zhaolou Coal Mine's seventh mining area,a combination of field measurements,numerical simulations,theoretical analysis and industrial experiments is employed to investigate the causes of frequent high-stress coal pillar impacts due to thick overburden movement,and a novel pressure fracturing method for high-stress isolated coal bodies to prevent rock bursts is introduced.PFC simulations reveal three loading modes as overburden thickness increases with mining field length,including uniform load,soil pressure arch and a combination of both.Stratum movement is divided into three stages such as bedrock fracture movement,initial rock-soil linkage and periodic rock-soil linkage.A quantification method for the fault coal pillar's load distribution curve is developed,considering load transfer mechanisms under fault isolation and sequential overburden conditions.An engineering model for stress-bearing in isolated coal bodies is established,along with criteria for instability and impact in the main tunnel.The frequent impact mechanism of high-stress coal pillars is explained by the coupling effect of rock-soil strata linkage loading and fault isolation,leading to stress concentration in fault coal pillars.The proposed pressure fracturing method reduces the elastic core's bearing capacity through hydraulic fracturing,promoting load redistribution and stress equalization for rock burst prevention.The water injection fracture pressure for the elastic core determined by industrial tests is approximately 30 MPa,with crack expansion and stress homogenization width exceeding 21.2 and 14.5 m.Monitoring and CT scan results indicate that elastic core fracturing reduces stress concentration,releases critical energy,and lowers the risk of impacts in isolated coal bodies.

关 键 词：采矿工程 深厚表土 大巷煤柱 断层 频繁冲击 水力压裂 

分 类 号：TD32[矿业工程—矿井建设]