基于采动裂隙特征规律下的高位钻孔优化研究

Research on Optimization of High-level Boreholes Based on Characteristics Law of Mining-induced Fractures

为了研究采空区上覆岩层裂隙发育和演化规律,确定最佳高位钻孔瓦斯抽采位置,采用3DEC数值模拟方法对贺西煤矿3#、4#煤层工作面推进过程采空区上覆岩层裂隙演化规律进行研究。结果表明,依据位移变化划分各测线的三带分布与公式计算三带范围一致,并确定最佳抽采区域为3#煤层上方21.48~28.6 m,最后通过选取2317工作面材料巷抽采钻场4个高位钻孔作为考察钻孔,经实际测量证明位于最佳抽采区域钻孔的抽采效果最好。

In order to study the fracture development and evolution law of overlying strata in goaf and determine the best gas extraction position of high-level boreholes,the 3DEC numerical simulation method was used to study the fracture evolution law of overlying strata in goaf during the advancing process of No.3 and No.4 coal seam working faces in Hexi coal mine.The results show that the distribution of the three zones of each measuring line according to the displacement change is consistent with the range of the three zones calculated by the formula,and the optimal extraction area is determined to be 21.48-28.6 m above the No.3 coal seam.Finally,four high-level boreholes in the 2317 working face material roadway extraction drilling field were selected as the investigation boreholes.The measurement results showed that the extraction effect of the boreholes in the best extraction area was the best.