含瓦斯煤加载损伤及渗透特性试验研究

Experimental Study on Loading Damage and Permeability of Coal Containing Gas

为加深对含瓦斯煤损伤与渗透特性认识,对新景矿含瓦斯原煤进行了不同瓦斯压力下的常规三轴加载和分段变速加载力学-渗透-声发射同步试验。试验结果表明:两种应力路径下,含瓦斯煤在加载破坏过程中的偏应力和渗透率随加载时间的变化均包含5个阶段,其声发射计数、能量、累计计数和累计能量随加载时间变化均包含4个阶段。分段变速加载条件下含瓦斯煤的力学与渗透特征参数对加载时间的响应相比声发射特征参数对加载时间的响应有一定的迟滞性。与常规三轴加载相比,分段变速加载条件下的声发射参数随加载时间的响应规律与实际采动条件下煤与瓦斯突出发生前兆规律更为吻合。该研究对于认识煤与瓦斯突出发生机理,指导煤与瓦斯突出防治具有一定的现实意义。

To deepen the understanding on the damage and permeability characteristics of coal containing gas,conventional triaxial loading and piecewise variable speed loading mechanics-permeability-acoustic emission synchronous tests were carried out for raw coal containing gas in Xinjing Mine under different gas pressure conditions.The results showed that,in the process of loading failure of raw coal containing gas under two stress paths,the variation of deviatoric stress and permeability included five stages,and the acoustic emission counting,energy,cumulative counting and cumulative energy all contained four stages.The response of mechanical and permeability parameters with loading time had a certain hysteresis compared with AE characteristic parameters under piecewise variable speed loading.Compared with the conventional triaxial loading,the response law of AE characteristic parameters with loading time under piecewise variable speed loading was more consistent with the precursory law of coal and gas outburst under the actual mining conditions.This research had a practical significance for understanding the mechanism of coal and gas outburst and for guiding the prevention and control of coal and gas outburst.