多层坚硬顶板特厚煤层综放工作面小煤柱护巷技术  

Small coal pillar technology in fully-mechanized top-coal caving face of multi layer hard roof and extra thick coal seam

作　　者：霍丙杰[1] 孟繁禄 李天航 宋子奇 靳京爵 黄宇轩 HUO Bingjie;MENG Fanlu;LI Tianhang;SONG Ziqi;JIN Jingjue;HUANG Yuxuan(School of Mining,Liaoning Technical University,Fuxin 123000,China;School of Safety Science and Engineering,Xinjiang Institute of Engineering,Urumqi 830023,China)

机构地区：[1]辽宁工程技术大学矿业学院,辽宁阜新123000 [2]新疆工程学院安全科学与工程学院,新疆乌鲁木齐830023

出　　处：《煤炭科学技术》2024年第3期13-23,共11页Coal Science and Technology

基　　金：国家自然科学基金资助项目(52174185);山西省科技计划揭榜招标资助项目(20191101015)。

摘　　要：为研究小煤柱护巷巷道的稳定性及其阻隔同层位邻近采空区灾害的特征,以大同矿区石炭系坚硬顶板特厚煤层开采为工程背景,采用理论分析、实验研究、数值模拟等研究方法,从小煤柱护巷巷道的稳定性和其是否具有阻隔同层位邻近采空区有害气体能力2个角度,综合分析小煤柱的合理尺寸及其在不同采动阶段渗透率的演化特征。针对同忻煤矿石炭系煤层8210工作面沿空掘巷小煤柱开采具体的开采条件,建立了双关键层采场内外应力场叠加的力学模型,推导出双关键层条件下沿空掘巷小煤柱合理尺寸的计算关系式,理论确定8210工作面小煤柱合理尺寸为6.0 m;应用DJG–Ⅱ型煤岩渗流测试装备,研究不同采动阶段小煤柱渗透率演化特征,试验确定在第3采动阶段小煤柱渗透率较初始渗透率增大了23倍,该阶段小煤柱基本失去了阻隔邻近采空区有害气体的能力。根据理论研究结果,现场选取6 m小煤柱进行工业性试验;根据试验研究结果,开采试验过程中对小煤柱进行了改性降透措施,在小煤柱表面及顶板距煤柱帮1500 mm范围内喷射厚层混凝土(100 mm)。实践表明:工作面回采过程中小煤柱护巷的回采巷道发生了一定的变形量,但是巷道变形在安全可控范围之内,巷道稳定,可实现安全回采;开采过程中8210工作面上隅角CH4气体浓度远低于邻近8305工作面采空区CH4气体浓度,表明小煤柱经过改性降透后具备了阻隔同层位邻近采空区有害气体的能力;开采实践也进一步验证了理论和试验研究成果的合理性和科学性。研究成果可以为类似条件下小煤柱护巷技术的推广应用提供参考。In order to study the stability of small coal pillar roadway protection and its characteristics of blocking disasters in adjacent goaf areas at the same layer,the mining of extra-thick coal seams with hard roofs in the Carboniferous mining area in Datong Mining Area was used as the engineering background,and theoretical analysis,experimental research,numerical simulation,etc.were used.From the two perspectives of the stability of the small coal pillar roadway protection tunnel and its ability to block harmful gases in adjacent goaf areas at the same layer,a comprehensive analysis is made of the reasonable size of the small coal pillar and the evolution characteristics of its permeability in different mining stages.Aiming at the specific mining conditions of small coal pillar mining in gob-side entry driving in 8210 working face of Carboniferous coal seam in Tongxin Coal Mine,a mechanical model of superposition of internal and external stress fields in double key strata is established,and the calculation formula of reasonable size of small coal pillar in gob-side entry driving under the condition of double key strata is deduced.The reasonable size of small coal pillar in 8210 working face is theoretically determined to be 6.0 m.The permeability evolution characteristics of small coal pillars in different mining stages were studied by using DJG-II coal rock seepage test equipment.It was determined that the permeability of small coal pillars in the third mining stage was 23 times higher than that in the initial test,and the small coal pillars in this stage basically lost the ability to block the harmful gases in the adjacent goaf.According to the theoretical research results,6 m small coal pillars were selected for industrial test.According to the experimental results,during the mining test,the small coal pillar was modified to reduce the permeability,and the thick layer concrete(100 mm)was sprayed on the sur-face and roof of the small coal pillar within 1500 mm from the coal pillar.The practice shows that a certain

关 键 词：多层坚硬顶板 沿空掘巷 多重采动 小煤柱合理尺寸 渗透率 

分 类 号：TD353[矿业工程—矿井建设]