中文摘要：

在不同的围压、轴压、渗透压组合条件下,对乡宁2号焦煤100mm×100mm×200mm的大尺寸煤样进行了瓦斯气体吸附前后的渗透性试验。结果表明：乡宁2号焦煤的渗透率随体积应力呈阶段性变化规律,在加载初期,渗透率随体积应力有一定程度增加,随后开始迅速降低;在加载后期,渗透率缓慢下降;体积应力较低时,提高渗透压能在一定程度上提高煤体渗透率,但是随着体积应力的增长,这一作用效果减弱;煤体吸附瓦斯后,在相同体积应力与渗透压条件下,煤体的渗透率下降十分明显,平均降低9.14%～26.99%。

英文摘要：

The permeability of coal is one of the most important parameters in CBM extraction.In this paper,the experimental study results of permeability in Xiangnin 2# coking coal specimens of large size（100 mm×100 mm×200 mm）are presented,which realistically simulates the change of permeability by gas adsorption under combination of different confining pressure.The result indicates that there are three stages of permeability with the change of volumetric stress.In the initiation of stress loading,permeability increases with the rise of volumetric stress,and then begins falling rapidly.In the later stage of stress loading,permeability drops slowly;Enhancing permeable stress will increase permeability to some extent when the volumetric stress is relatively low,as the growth of volumetric stres,the effects will be weaken;after the samples adsorbes methane,permeability drops obviously on the condition of the same volumetric stress and permeable stress,the average of decline degree is about 9.14% to 26.99%.