煤矿深部开采卸荷消能与煤岩介质属性改造协同防突机理
Coordinated prevention mechanism of pressure-relief and coal and rock properties modification for coal and gas outburst in deep mining of coal mines
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摘要: 由于煤矿深部煤岩体物性、应力、瓦斯等因素显著改变,出现了应力主导型突出、低瓦斯压力突出等新的灾害特征。为了更好地指导煤矿深部突出防治工作,基于煤与瓦斯突出关键结构体致灾理论,结合所建立的易突出构造煤体渗透率演化理论模型,揭示了煤矿深部开采卸荷消能与煤岩介质属性改造协同防突机理。研究表明:煤与瓦斯突出灾害防控的核心是高效抽采瓦斯,其关键是设法降低地应力;降低易突出构造煤体所受地应力大小,可起到降低弹性潜能、提升煤层渗透率、促进瓦斯高效抽采、降低瓦斯内能等多重效应;煤矿深部开采煤与瓦斯突出灾害防控应因地施策,从卸荷消能和煤岩介质属性改造两方面着手,重点区域在采用卸压增透和瓦斯抽采措施后,还可采取一些提高煤体强度、抑制瓦斯解吸等改性措施,确保煤矿深部采掘作业的安全。Abstract: The deep mining of coal mines leads to some significant changes in the physical properties of coal and rock, stress environment and gas occurrence law. New disaster features such as stress-driven gas outburst and coal and gas outburst under low gas pressure condition have appeared. In order to guide the prevention and treatment of coal and gas outburst in deep coal mines,the theoretical permeability model of tectonic coal body prone to outburst is estab-lished. The coordinated prevention mechanism of pressure-relief and coal and rock properties modification for coal and gas outburst is revealed based on the key structural body theory of coal and gas outburst. The research result shows that the core of prevention and control coal and gas outburst is efficient gas extraction,and the key is to reduce ground stress. This pressure relief has multi-effects of reducing elastic strain energy,improving the coal permeability,promo-ting gas extraction and reducing the gas internal energy. The prevention and control measures of coal and gas outburst in deep coal mines should be implemented according to two concrete conditions including relieving pressure and reforming coal & rock medium property. In some special areas of coal mines,after adopting the pressure relief measures and implementing gas extraction,other auxiliary measures should be taken to improve the outburst resistance and restrain the gas desorption to ensure mining safety in deep coal mines.