高瓦斯多煤层大采高工作面覆岩裂隙演化规律研究

高瓦斯多煤层矿井运用大采高技术以实现矿井高产高效,开采工艺不同导致工作面瓦斯涌出规律的变化。以沁水煤田15#煤层大采高工作面煤层赋存条件和覆岩分布特征为背景开展采动覆岩裂隙演化规律研究,运用UDEC数值模拟大采高工作面在不同推进距离时覆岩裂隙形态发育及位移量,并提出基于示踪原理的实测覆岩裂隙发育规律的验证方法。研究表明:大采高工作面推进至120m时,煤层上覆岩层裂隙极限发育高度为65m,大采高工作面上邻近层8#煤层处于采动卸压范围,示踪气体法现场测试数据验证了数值模拟的准确性。由于大采高工作面覆岩裂隙发育范围扩展至上邻近层8#煤层,所以工作面回采过程中应增加上邻近层瓦斯抽采工艺。

Research on the Evolution Law of Overburden Rock Cracks on High-gas Multi-seam Large Mining Height Working Face

Large mining height technology is used in high-gas multi-seam mines to realize high production and high efficiency, but a difference in mining technology may lead to a change in gas emission regularity on working face. This research was carried out on the evolution law of mining overburden rock cracks on the background of coal seam occurrence conditions and overburden rock distribution characteristics on a large mining height working face in No.15 Coal Seam, Qinshui Coalfield. The research used UDEC to numerically simulate the morphological development and displacement of overburden rock cracks on the large mining height working face at different advancing distances, and then a tracing principle-based validation method was put forward for measuring the development regularity of overburden rock cracks. According to the research, as the large mining height working face advanced to 120m, the limiting development height of the overburden rock cracks in the coal seam reached 65m, and No.8 Coal Seam, the upper neighboring coal seam of this large mining height working face, lied in the relief range of mining pressure. The field test data obtained by the tracer gas method validated the accuracy of the numerical simulation. Since the overburden rock cracks propagated to the upper neighboring coal seam No.8 Coal Seam, a gas extraction technology applying to the upper neighboring coal seam should be adopted in the stoping process on the working face.