School of Safety Engineering, China University of Mining & Technology Shenyang Research Institute, China Coal
Technology and Engineering Group State Key Laboratory of Coal Safety

为了提高高位钻孔的瓦斯抽采效果,以漳村煤矿2203综放工作面为工程背景,结合3号煤层的开采条件,首先应用关键层理论确定了3号煤层的顶板裂隙带位于其上方12.8~36.5 m,再采用薄板理论和数值模拟相结合的方法,研究了3号煤层顶板裂隙带的分布和演化特征。结果表明,随工作面的推进,上覆岩层裂隙由下而上逐渐发育,工作面推进至60 m时主关键层以下形成较密集的裂隙,至110—170 m时部分主关键层岩块裂隙闭合,并在下部形成2个小范围压实区并逐渐扩展而形成大面积压实区。煤层顶板裂隙经历了一个产生—发育—部分闭合的过程。基于以上研究结果,对2203工作面2组钻场内的高位钻孔布置参数进行了优化。现场应用结果表明,优化后单孔平均瓦斯抽采量增加了2.39~3.03倍,单位钻孔工程效益提高2.00~2.58倍。

In order to improve the gas drainage effect of high level borehole, taking No.2203 fully-mechanized top coal caving face of Zhangcun Coal Mine as the e ngineering background, combining with the mining conditions of No.3 coal seam, according to key stratum theory, the No. 3 coal seam roof fractured zones distribution range was confirmed in the range of 12. 8 ~ 36. 5 meters above the roof. By using the combined method of the thin plate theory and numerical simulation, the No. 3 coal seam roof fractured distribution and evolution characteristics during the working face mining were studied. The results showed that overburden rock stratum crack grad ually grew from the bottom up as the face advancing. At 60 meters, the dense fracture was shaped under the main key stratum. The partial main key stratum rock crack enclosed and two small compacting areas were formed between 110 meters to 170 meters, and it was gradually broaden. The coal seam roof fractured had experienced an emerge, grow and partial enclose process. Based on the findings, the disposition parameters of two group drilling field high level boreholes in No. 2203 fully-mechan ized top coal caving face was optimized. The field application showed that the amount of the optimized unit borehole gas drainage increased by 2. 39 ~ 3. 03 times, unit borehole project benefit improved by 2. 00~ 2.58 times.

国家科技重大专项资助项目(2011ZX05041-003)；“十二五”国家科技支撑计划资助项目(2012BAK04B01)；