坚固性系数对含瓦斯煤渗透率影响的实验研究

Experimental Study of the influence of Solidity Coefficient on Permeability of Coal Containing Gas

为了研究煤的坚固性系数与含瓦斯煤渗透率之间的关系,以贵州五轮山、玉舍及响水煤矿3层坚固性系数符合梯形分布煤层的煤样为研究对象,利用自主研发的三轴渗透仪,进行了不同坚固性系数条件下,恒温-变平均有效应力和恒平均有效应力-变温的三轴渗流实验,结果表明:(1)含瓦斯煤的渗透率随平均有效应力的增大而减小,并服从形如K(σ)=ke-λσ的负指数分布,且含瓦斯煤渗透率的减小趋势与煤体所受平均有效应力的大小有关;(2)同一坚固性系数煤样的渗透率随温度的增加而降低;(3)相同实验条件下,含瓦斯煤的渗透率随煤样坚固性系数的增加而增加;(4)相同的平均有效应力条件下,煤的坚固性系数对含瓦斯煤渗透率的影响程度大于温度对渗透率的影响。研究结果对贵州瓦斯灾害的防治提供了一定的理论依据。

For studying the relationship between the solidity coef- ficient of coal containing gas and its permeability, the triaxial permeability experiments of coal with different solidity coefficient under the conditions of constant temperature, variant average ef-fective stress and constant average effective stress,variant tem- perature carried out by a self - developed triaxial permeameter. The coal samples with gradient distribution of solidity coefficient- were excavated from Wulunshan coal mine, Yushe coal mine, and Xiangshui coal mine in Guizhou province. The results showed that：（1） The permeability of coal samples containing gas de- creased with the average stress increasing, and the figure con- formed to negative exponential distribution asK（t r） = ke-λб , and the decreasing trend of permeability of coal samples contai- ning gas was related to the value of average stress suffered by coal samples; （2） The permeability of coal samples with the same solidity coefficient was decreasing while temperature in- creasing ; （3） Under the same experiment condition, the perme- ability of coal samples containing gas increased with their solidity coefficient increasing; （4） Under the same average stress, the in- fluence of solidity coefficient of coal samples on the their perme- ability was greater than that of temperature. The results of study provided a theory basis for the prevention and control of gas out- burst disasters in Guizhou province.