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为探索同一应力加卸载路径下2种典型煤样(原生结构煤及构造煤)的瓦斯渗透规律,用3轴应力瓦斯渗流模拟装置,对2种原煤试件不同瓦斯压力承压时的瓦斯渗透特性进行试验研究。结果表明,加载阶段,随着加载应力的增大,2种煤样的渗透率均呈下降趋势,且初期降幅最急剧,当围压从0升到3 MPa时,2种煤样的渗透率分别下降64%和70%;卸载阶段,渗透率随着应力的减小而增大,围压完全卸载后,2种煤体的渗透率分别恢复到初始值的25%和50%;在同样的应力条件下,有效应力的增加对原生结构煤的影响作用大于煤基质收缩,渗透率随着瓦斯压力的增加而增大,而对构造煤则相反,渗透率随着瓦斯压力的降低而增大。
In order to explore the gas permeation law of two kinds of typical coal samples (primary structure coal and tectonic coal) under the same stress loading and unloading path, the gas permeation under different gas pressure bearing pressures Characteristics of experimental study. The results show that with the increase of loading stress, the permeability of the two coal samples shows a downward trend during the loading phase, and the initial decline is the most rapid. When the confining pressure increases from 0 to 3 MPa, the permeability of the two coal samples Respectively, decreased by 64% and 70% respectively. During the unloading phase, the permeability increased with the decrease of stress. After the unloading of the confining pressure, the permeability of the two kinds of coal recovered to 25% and 50% of the initial value, respectively. Of the stress conditions, the increase of effective stress on the primary structure of coal is greater than the impact of coal matrix shrinkage, permeability increases with the gas pressure increases, while the construction of coal on the contrary, the permeability decreases with the gas pressure increases Big.