School of Mines, China University of Mining and Technology
Inner Mongolia Zhungeer Banner Kinetic Coal Industry Co., Ltd.

浅埋巨厚煤层开采极易诱发覆岩裂隙贯通地表形成漏风通道,造成工作面通风管理困难及井下遗煤自燃。以内蒙古大饭铺煤矿61202工作面为研究对象,采用UDEC数值模拟分析了工作面开采上覆岩层应力变化及破断特征,探究了覆岩裂隙演化规律及其分形特征。结果表明:浅埋巨厚煤层综放开采条件下上覆岩层应力将经历增压、减压和复压三个阶段;可将工作面推进距离0~50m、60~240m、245~450m划分为“加速升维-减速升维-平稳稳维”三个裂隙发育阶段,全开采阶段分形维数D在1.011~1.341之间;基于裂隙发育三阶段的特点提出不同阶段裂隙发育控制方法,以此确保工作面安全生产。研究成果有助于揭示西部浅埋巨厚煤层综放开采裂隙发育规律。

The mining of shallow burial extremely thick coal seams can easily induce the formation of air leakage channels through the surface of overlying rock fractures, resulting in difficulties in ventilation management of the working face and spontaneous combustion of downhole residual coal. Taking the 61202 working face of Dafanpu Coal Mine in Inner Mongolia as the research object, UDEC numerical simulation is used to analyze the stress changes and fracture characteristics of the overlying rock strata during the working face mining, and the fracture evolution law and its fractal characteristics of overlying rock are explored. The results indicate that under the condition of shallow burial extrememly thick coal seam fully mechanized mining, the stress of the overlying rock strata will go through three stages: pressure increase, pressure decrease, and re-pressure; The advancing distance of the working face of 0-50 m, 60-240 m, and 245-450 m can be divided into three stages of fracture development: "accelerated dimension raising-decelerated dimension raising-stabilize dimension smoothly". The fractal dimension D during the fully mining stage is between 1.011 and 1.341; Based on the characteristics of the three-stage development of fractures, different control methods for fracture development at different stages are proposed to ensure safe production of the working face. The research results are helpful in revealing the development law of fractures in shallow burial extremely thick coal seam fully mechanized mining in the western region.