在煤层瓦斯含量增大的条件下进行集中开采,不可避免地就要同时采取一种提高瓦斯抽放效果的措施,以降低巷道中的瓦斯涌出量,保证巷道的掘进速度。目前,在卡拉干达煤田广泛应用倾斜壁式开采法开拓新水平。此方法可以使开采更加集中,并能提高工作面产量。但是在瓦斯含量增大的条件下,为加快下山巷道的掘进,须要采用新的抽放瓦斯的方法,因为现有的抽放方法都不能保证大量的瓦斯排放。 It is inevitable to take measures to improve the gas drainage effect at the same time when centralized mining is carried out under the condition of increasing coal seam gas content so as to reduce the gas emission in the tunnel and ensure the tunneling speed. Currently, extensive use of inclined wall mining method opens up a new level in the Karaganda coalfield. This method can make the mining more concentrated, and can improve the production of face. However, with the increase of gas content, new methods of gas drainage are needed to speed up the tunneling of down-hill roadway because the existing gas drainage methods can not guarantee a large amount of gas emission.