浅埋近煤层群采动“三区”漏风裂隙场时空演化规律数值模拟  

Numerical simulation on the spatiotemporal evolution of air leakage fissure field of"three zones"in shallow-buried coal seam group mining

作　　者：马亮 孟威 高亮 张壮壮 宋涛 冯雄 夏同强[2,3] MA Liang;MENG Wei;GAO Liang;ZHANG Zhuangzhuang;SONG Tao;FENG Xiong;XIA Tongqiang(Shaanxi Coal and Chemical Industry Group Shenmu Ningtiaota Mining Co.,Ltd.,Yulin,Shaanxi 719300,China;Carbon Neutrality Institute,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Henan Key Laboratory for Green and Efficient Mining&Comprehensive Utilization of Mineral Resources,Henan Polytechnic University,Jiaozuo,Henan 454150,China)

机构地区：[1]陕煤集团神木柠条塔矿业有限公司,陕西省榆林市719300 [2]中国矿业大学碳中和研究院,江苏省徐州市221116 [3]河南省矿产资源绿色高效开采与综合利用重点实验室,河南省焦作市454150

出　　处：《中国煤炭》2024年第3期69-79,共11页China Coal

基　　金：国家自然科学基金项目(52074284);河南省矿产资源绿色高效开采与综合利用重点实验室开放基金(KCF2206);中国矿业大学中央高校基本科研业务费专项资金(2023KYJD1002)。

摘　　要：浅埋近煤层群采动下,地面采空区工作面“三区”之间易形成连通的漏气通道引发工作面低氧和采空区煤自燃,如何厘清采动效应下浅埋煤层群“三区”漏气通道的时空分布演化规律是有效防控煤自燃和低氧的关键。以陕煤柠条塔煤矿S1232工作面为研究背景,采用理论与数值模拟相结合的方法,研究了单一煤层、复合煤层重复开采下覆岩破坏特征,分析了煤层间距与采厚对裂隙二次发育的影响规律。结果表明:浅埋近煤层群开采下上覆岩层裂隙仅存在垮落带与裂缝带,主关键层破断后裂缝带快速发育至地表,关键层周期破断控制地表裂隙周期生成与下沉;上煤层裂隙密度发育由原始阶段先后经历快速增长、稳定和二次增长3个阶段;随采厚增大,各区间裂隙密度增大,大裂隙发育更充分,裂隙宽度整体增大;随煤层间距增大,小于0.2 m的裂隙宽度随采厚增大,且增加的速度逐渐加快,大于0.2 m的裂隙宽度随采厚增大,但增加速度逐渐变缓;采厚相同时,裂隙宽度大于0.2 m的裂隙密度随着煤层间距的增大逐渐减小。Under the mining influence of shallow-buried coal seam group,the connected air leakage channel is easily formed between the"three areas"of surface ground-goaf-working face,which leads to low oxygen in working face and coal spontaneous combustion in goaf.How to clarify the spatiotemporal distribution and evolution law of the gas leakage channel in the"three zones"of shallow coal seam group under the influence of mining is the key to effectively prevent and control coal spontaneous combustion and low oxygen.Based on S1232 working face of Ningtiaota Coal Mine in Shaanxi,the failure characteristics of overburden under repeated mining of single coal seam and composite coal seams were studied by combining theory study and numerical simulation,and the influence of layer spacing and mining thickness on secondary development of cracks was analyzed.It was found that the cracks were only developed in caving zone and fractured zone in overlying strata during shallow coal seam group mining,and the fractured zone developed rapidly to the surface ground after the fracture of the main key layer,and the periodic fracture of the key layer controlled the periodic formation and subsidence of the surface fissure;the development of fracture density in upper coal seam was divided three stages:rapid growth,stable growth and secondary growth;with the increase of mining thickness,the fracture density in each zone increased,the large fracture developed more fully,and the fracture width overall increased;with the increase of layer spacing,cracks smaller than 0.2 m width increased with the mining thickness,and the increasing speed was gradually accelerated,while cracks larger than 0.2m width increased with the mining thickness,but the increasing speed was gradually slow;with the same mining thickness,the density of large fractures with widths greater than 0.2 m decreased with the increase of layer spacing.

关 键 词：浅埋近煤层群 重复采动 漏气通道 裂隙宽度 煤层间距 采厚 数值模拟 

分 类 号：TD325[矿业工程—矿井建设]