综放开采顶煤瓦斯渗透性研究

Study of gas permeability in top-coal during mechanical longwall top-coal caving mining

综放开采由于采高的加大,导致采场前方顶煤中瓦斯渗透性与分层开采有较大的差异.针对目前综放开采瓦斯渗透性理论存在的问题,在有关研究的基础上,结合综放开采的实际,通过引入等效弹模、裂隙不均匀系数及有效应力对已有岩体渗透系数表达式进行修正,从而给出综放开采采场前方顶煤中瓦斯渗透系数的数学表达式,并给出现场计算实例.图1,参14.

During mechanical longwall top coal mining, the gas permeability in top coal ahead of working face has bigger difference compared with slice mining due to the increase of mining height. The present problems of gas permeability theory are discussed. The features of longwall mining with top coal caving is taken into account, and the existing formula of rock permeabiliuy is revised by introducing equivalent modulus and inhomogeneity coefficient of topcoal fracture as well as effective stress, at last the formula of the top coal permeability coefficient is put forward, which is validated by case study. 1fig.,14refs.