摘要
Abstract
To investigate the gas migration law in the goaf before and after the pre-splitting and weakening of the mining-induced overburden roof during the extraction of the 9#coal seam in a mine in Inner Mongolia,a three-dimensional geological numerical model of the goaf was established using COMSOL Multiphysics based on the simulated fracture zone development before and after roof pre-splitting.The distribution patterns of gas accumulation zones were simulated and analyzed under different working face advance distances(80 m,120 m,200 m,250 m),different air intake volumes,and before and after the pre-splitting and weakening of the mining overburden roof.The results show that as the working face advances continuously,gas in the goaf displays obvious accumulation characteristics,with the concentration exhibiting a gradient-increasing trend along the strike direction and eventually reaching a stable equilibrium state.After roof fracturing is implemented,the gas concentration within the fracture zone increases significantly,and the extent of the high-concentration gas region in the deep goaf on the return airway side is reduced,effectively improving the conditions for borehole drainage.The research results can provide a theoretical basis for the optimization of pressure-relief gas drainage technology.关键词
卸压瓦斯/瓦斯运移/采空区/数值模拟/裂隙带Key words
pressure-relief gas/gas migration/goaf/numerical simulation/fractured zone分类
矿业与冶金
