以张集矿北区为研究对象,介绍了在保护层开采后未及时进行瓦斯抽采,煤岩体重新压实条件下水力冲孔的现场试验过程,并与仅进行保护层开采的卸压增透和在未受采动影响的实体煤层中进行水力冲孔的卸压增透现场试验效果进行了对比。结果表明,在受采动影响的煤层中进行水力冲孔,对煤层进行二次卸压,可使水力冲孔的有效抽采半径增大到16 m,使瓦斯抽采率提高到46%,并且在受采动影响的煤层中进行水力冲孔可降低水射流的破煤压力。

Taking the north area of Zhangji Mine as a study object, the paper introduced the site experiment process of the hydraulic borehole flushing under the re compacted conditions of the coal and rock masses after the protective seam mined with no gas drainage operation conducted on time .A comparison was conducted bet ween the site experiment effects of the pressure releasing and permeability improvement with hydraulic borehole flushing in the coal seam with no mining activities and the pressure releasing and permeability of the protective seam mining.The results showed that the hydraulic borehole flushing conducted in seam with no mining activit y influences could have a secondary pressure releasing in the seam and could make the effective drainage radius with the hydraulic borehole flushing increased to 16 m.Thus the gas drainage rate could be increased by 46% and the hydraulic borehole flushing in the seam with no mining influence could reduce the coal breaking press ure of the water jet.

国家自然科学基金资助项目(50874005)；