煤与瓦斯突出的土力学分析

为了探索煤与瓦斯突出机理,根据岩体结构分类方法,把破坏类型为Ⅲ,Ⅳ,Ⅴ类的煤视为散体结构岩体.借鉴土力学流土失稳理论分析煤与瓦斯突出机制,把临界失稳梯度作为煤体的抗突强度指标.通过对煤体瓦斯压力梯度变化过程的分析,指出低透气性煤比高透气性煤更容易发生高强度突出的原因是由于低透气性煤的"失稳分层"的单位体积煤体具有更高的气体膨胀能.提出隔渗帷幕法和反滤层法2种控突思路.

Analysis on mechanism of coal and gas outburst with principles of soil mechanics

In order to study the mechanism on coal and gas outburst,based on the standards for classification of rock mass structure,damage degree Ⅲ-Ⅴ coal seam was regarded as loose structure rock mass.Refer to the theory of soil mechanics on soil flowing,it was supposed that coal and gas outburst may be induced by gas seepage.The critical gas pressure gradient was thought as a strength index preventing outburst.Through the analysis of the gas pressure gradient,a conclusion was drawn that low permeability coal could occur easily high outburst intensity because of its high expansion energy after losing stability.Two new approaches of controlling outburst were suggested,which included setting seepage proof curtain and setting anti-filter layers.