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前言 煤矿瓦斯抽放是为了:①见煤、采煤之前予先进行瓦斯抽放,降低掘进头及工作面的瓦斯浓度,弥补通风量的不足;②利用人工卸压以防止瓦斯突出两个目的而进行的。为提高瓦斯抽放效率,降低钻孔成本,加大瓦斯抽放孔的直径是个有效的方法。也有的文献提出了瓦斯抽放效率与钻孔孔径成比例。
Preface Coal mine gas drainage is to: ① see coal, coal mining prior to the first gas drainage, reduce head and face gas concentration, make up for lack of ventilation; ② the use of artificial pressure relief to prevent gas out of two purposes And proceed. In order to improve gas drainage efficiency and reduce drilling costs, it is an effective way to increase the diameter of gas drainage holes. Some literature also proposed gas drainage efficiency is proportional to the hole diameter.