2种原煤样渗透性对比试验研究

摘要

为了研究构造煤原煤样与硬煤原煤样渗透率变化规律的异同,用三轴渗流装置对2种原煤样进行了瓦斯渗透性试验.在改变单一因素条件下,分别研究围压和瓦斯压力对2种煤样渗透性的影响,同时研究轴压加载及卸载过程中2种原煤样的渗透率变化规律.结果表明;瓦斯压力恒定时,2种煤样的渗透率都随围压的增大而减小;围压恒定时,瓦斯压力在0.2~0.6 MPa范围内,2种煤样的渗透率都随瓦斯压力增大而减小;瓦斯压力及围压同时保持恒定时,2种煤样的渗透率都随轴压增大不断减小,2种煤样在卸载阶段渗透率均不断增大,但均没有恢复到加载前的渗透率,构造煤煤样渗透率恢复率比硬煤小,说明构造煤加载过程中发生塑性破坏比例大于硬煤.%In order to study the similarities and differences of permeability change between raw coal samples of tectonic coal and hard coal, the gas permeability tests of two kinds of raw coal samples were carried out by using the triaxial seepage device.The influence of confining pressure and gas pressure on permeability of two kinds of raw coal samples under the condition of changing single factor were studied respectively, and the variation laws about permeability of two kinds of raw coal samples during axial pressure loading and unloading process were studied.The results showed that both the permeability of two kinds of coal samples decrease with the increasing confining pressure when the gas pressure is constant.When the confining pressure keeps constant, the gas pressure is in the range of 0.2-0.6 MPa, and both the permeability of two kinds of coal samples decrease with the increasing gas pressure.When both the gas pressure and confining pressure keep constant, both the permeability of two kinds of coal samples decrease with the increasing axial pressure.Both the permeability of two kinds of coal samples in the unloading stage are increasing, but they are not recovered to the permeability before loading.The recovery ratio of permeability of tectonic coal sample is smaller than that of hard coal, which indicates that the plastic destruction proportion of tectonic coal is larger than that of hard coal in loading process.