关键词: 急倾斜煤层, 裂隙发育, 瓦斯流动通道, UDEC数值模拟, 瓦斯抽采

Abstract: In order to study the roof fracture development and its effect on gas drainage during steep long wall full-mechanized caving mining，combined with relevant theories of elastic-plastic mechanics and fracture mechanics，the mechanics criterion of fracture development in steep coal seam mining has been analyzed，and the gas flow channel has been partitioned as gas isolated channel area, gas transition area and gas network area. Furthermore, the overlying rock fracture development during steep super high coal seam long wall top coal caving mining under the condition of different dip angle of coal seam in Baojishan coal mine has been analyzed，and the changing rules of gas flow channel’s area configuration with the seam angle changing has been obtained．The results of the study shows that the upper part of gas network area are the main areas that the artificial guide channel should run through，and the distribution range of the areas tends to the upper face end and its height increases with the seam angle increasing. The gas drainage plan can be determined according to numerical simulation and theoretical calculation，which will achieve good effect in engineering practice．

Key words: steep coal seam, fracture development, gas flow channel, UDEC numerical simulation, gas drainage