浅埋煤层开采地表塌陷特征及采空区渗流规律研究  

Study on the characteristics of surface subsidence and seepage law of goaf in shallow-buried seam mining

作　　者：李瑞楼 卞涛 LI Ruilou;BIAN Tao(Bulianta Coal Mine,China Energy Shendong Coal Group,Ordos,Inner Mongolia 017000,China)

机构地区：[1]国能神东煤炭集团有限责任公司补连塔煤矿,内蒙古自治区鄂尔多斯市017000

出　　处：《中国煤炭》2022年第S01期188-196,共9页China Coal

摘　　要：为探究浅埋煤层长壁采空区地裂缝漏风致灾机理,针对鄂尔多斯李家壕煤矿厚煤层、薄基岩、厚松散覆盖层等特殊开采条件,采用现场实测结合数值模拟的方式,研究了不同诱发因素及不同发展阶段下,各类裂缝发育形态特点、尺度特征及漏风状态,明确了地表漏风源及漏风范围,模拟了采空区速度场、氧浓度场分布情况,预测了采空区自燃危险区域,并给出工作面最小推进速度。研究结果表明,覆岩裂缝带最大发育高度可达52.3 m,为采高的11.6倍,滞后工作面发育的塌陷型裂缝是地表的主要漏风通道,随着基本顶破断周期性出现,平均间距15.8 m,当裂缝处于贯通发展阶段时,地表呈现不同程度的漏风,且单条裂缝存在多处同时漏风的现象,随着裂缝距工作面水平距离的不断增加,裂缝逐步自然愈合,受压力分布影响,地表漏风风流主要作用于采空区回风侧,在加大回风侧渗流速度的同时补充了回风侧氧浓度,使回风侧渗流影响范围向采空区深部方向移动。整体来看,进风侧氧化升温带宽度(100 m)大于回风侧宽度(37 m),工作面推进速度保持在3.1 m/d以上时采空区无自燃危险。In order to explore the disaster-causing mechanism of ground fissure air leakage in longwall goaf of shallow-buried coal seam,aiming at the special mining conditions of thick coal seam,thin bedrock and thick loose overburden of Lijiahao Coal Mine in Ordos,the characteristics of fissure development morphology,scale and air leakage state in different induced factors and development stages were studied by the combination of field measurement and numerical simulation,the source and range of surface air leakage were defined,the distribution of velocity field and oxygen concentration field in goaf were simulated,the spontaneous combustion danger zone was predicted,and the minimum advancing speed of working face was given.The study results show that the maximum development height of overburden fracture zone is 52.3 m,which is 11.6 times of mining height;the collapse-type fissures developed lagging behind the working face are the main air leakage channels on the surface;with the basic roof breaking occurring periodically,the average spacing is 15.8 m;when the fissures are in the cut-through development stage,the surface presents different degrees of air leakage,and there are multiple simultaneous air leakage phenomena in a single fissure;with the increase of the horizontal distance from the working face,the fissures gradually heal naturally;affected by the pressure distribution,the surface air leakage mainly acts on the return air side of the goaf,it increases the seepage velocity of the return air side and supplements the oxygen concentration of the return air side,so that the influence range of the return air side seepage moves to the deep direction of the goaf.As a whole,the width of the oxidation temperature-rise zone at the air inlet side(100 m)is larger than that at the air return side(37 m),and there is no danger of spontaneous combustion in the goaf when the advancing speed of the working face is kept above 3.1 m/d.

关 键 词：浅埋煤层 地裂缝 地表漏风 自燃危险区域 采空区流场 

分 类 号：TD327[矿业工程—矿井建设]