孟巴矿强含水体下分层开采覆岩导水裂隙带发育规律  

Development law of water-conducting fracture zone in overlying rock with layered mining under strong water-bearing body in Barapukuria coal mine

作　　者：余学义[1,2] 穆驰 李剑锋[3] YU Xueyi;MU Chi;LI Jianfeng(School of Energy Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Key Laboratory of Western Mine and Hazard Prevention,Ministry of Education,Xi’an 710054,China;Xuzhou Coal Mining Group,Xuzhou 221000,China)

机构地区：[1]西安科技大学能源学院,陕西西安710054 [2]西部矿井开采及灾害防治教育部重点实验室,陕西西安710054 [3]徐州矿务集团有限公司,江苏徐州221000

出　　处：《煤炭学报》2022年第S01期29-38,共10页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51874230,52074208)

摘　　要：孟巴矿地质条件特殊复杂,多种灾害交织,特别是矿井水害对安全生产构成了严重威胁。导水裂隙带高度探测与保水开采密切相关,控制导水裂隙带发育高度是为了保证LDT隔水层稳定性,避免在承压水体的作用下使隔水层被击穿。结合孟巴矿特殊地质条件,给出矿井地质开采条件具有开采煤层厚、开采煤层顶板砂岩层厚硬和上覆松散含水层UDT厚的“三厚二硬一强”特征,覆岩为隔水——结构关键层结构类型,基岩中缺少有效的隔水层的结构特征,提出基岩含水层随分层开采递进疏放,保证LDT隔水层的有效隔水性能,阻滞UDT水体渗漏到井下,形成强含水体下特厚煤层分层开采的“上保下疏”安全开采模式。借助360°旋转井下电视全孔壁成像系统,分析钻孔冲洗液漏失量和水位变化情况,应用物理模拟方法和数值计算模拟方法,模拟分析了不同分层、不同采高,采用不同采煤方法,覆岩导水裂隙带发育规律和覆岩移动破坏规律,完成了钻孔探测工作和数据分析,并与物理相似模拟和数值模拟结果进行对比,证实了实验模拟与探测数据结果基本一致。研究表明,当累计开采高度为8.5 m时,分层开采导水裂隙带高度呈快速增长模式;当累计开采高度介于13~15 m时,导水裂隙带发育高度趋于平缓且不再增长;1,2分层开采对导水裂隙带高度的增长率贡献大,主要是1,2分层开采使覆岩裂缝增多,裂缝增多表现为岩性变软;1,2分层开采导水裂隙带高度与开采厚度基本呈线性增长,2分层开采导水裂隙带高度增幅为1分层的109%,随分层厚度增加导水裂隙带高度有增大趋势,导水裂隙带高度整体呈马鞍形分布。工作面分层协调开采有效降低了覆岩导水裂隙带发育高度,保护了UDT含水层不发生泄露,形成了孟巴矿强含水体下厚煤层安全开采模式。The geological conditions of the Barapukuria coal mine are particularly complex,multiple hazards are intertwined,especially the mine water hazards pose a serious threat to safe production.The detection of the height of water-conducting fissure zone is closely related to the water-retaining mining.Controlling the development height of the water-conducting fracture zone is to ensure the stability of the LDT water barrier and avoid the water barrier from being broken down under the action of the confined water body.Combining with the special geological conditions of Barapukuria coal mine,the geological mining conditions of the mine show the characteristics of“three thick,two hard and one strong”,such as the thickness of the mining coal seam,the thickness of the sandstone layer on the roof of the mining coal seam,and the thickness of the overlying loose aquifer UDT.The overburden is water-proof-key layer structure type.The bedrock lacks the structural characteristics of an effective water barrier.It is proposed that the bedrock aquifer is progressively diverted with layered mining to ensure the effective water barrier performance of the LDT water barrier and block the UDT water body leakage into the mine,forming a safe mining mode of“upper protection and lower dredging”for slicing and mining of extra-thick coal seams under strong water-bearing bodies.With the help of 360°rotating downhole TV full-hole wall imaging system,the leakage of drilling fluid and the change of water level are analyzed.The physical simulation methods and numerical calculation simulation methods are applied to comprehensively simulate and analyze the height development law of the water-conducting fissure zone in the overburden and the movement and failure law of the overlying strata with different layers,different mining heights and different coal mining methods.The drilling detection work and data analysis,and the comparison of the results of physical similarity simulation and numerical simulation are completed.It is confirmed that th

关 键 词：三厚二硬一强 分层开采 UDT含水层 LDT隔水层 导水裂隙带 

分 类 号：TD745[矿业工程—矿井通风与安全]