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通过对突出危险煤渗透性试验研究,系统分析了不同围压、不同瓦斯压力和不同应力-应变状态条件下突出煤样的渗透特性,分别建立了突出危险煤的渗透性与围压、瓦斯压力和应力-应变等主要控制因素之间的定性和定量关系,探讨了不同载荷条件下突出危险煤渗透性的控制机制和变化规律。研究结果表明,载荷条件对突出危险煤的渗透性具有重要影响:(1)在固定瓦斯压力条件下,突出危险煤样的渗透率随围压的增大而减小,且服从指数函数变化规律。(2)在固定围压条件下,受Klinkenberg效应影响,渗透率与瓦斯压力之间大致呈“V”字型变化;Klikenberg效应发生在瓦斯压力p<1MPa的范围内。(3)在三轴压缩下的应力-应变全过程中,不同载荷条件下突出危险煤样的渗透率-应变曲线变化趋势几乎一致,且都呈“V”字型走势;在微裂隙闭合和弹性变形阶段,煤样渗透率随应力增大而减小;进入屈服阶段后,渗透率达到最小值并在峰值强度到达之前完成反超过程;峰值强度之后渗透率持续增大直至试验结束;煤样渗透率反超后的变化要较反超前变化平缓。
Based on the experimental study on the permeability of prominent dangerous coal, the permeability characteristics of protruding coal samples under different confining pressures, different gas pressures and different stress-strain conditions were systematically analyzed. The permeability and confining pressure, confining pressure and gas pressure And stress-strain and other major control factors between the qualitative and quantitative relationship between the different load conditions to explore the prominent danger of coal permeability control mechanism and changes in law. The results show that the loading conditions have an important influence on the permeability of coal with prominent danger: (1) Under the condition of fixed gas pressure, the permeability of critical coal samples decreases with the increase of confining pressure and obeys the law of exponential function . (2) Under the confining confining pressure condition, the Klinkenberg effect affects the approximate “V” shape change between permeability and gas pressure; Klikenberg effect occurs when the gas pressure p <1MPa. (3) In the whole process of stress-strain under triaxial compression, the trend of permeability-strain curves of coal samples with different stress conditions is almost the same and all show “V” In the closed and elastic deformation stage, the permeability of coal samples decreases with increasing stress. After entering the yielding phase, the permeability reaches the minimum value and the process of anti-overtaking is completed before the peak intensity reaches. After the peak intensity, the permeability continues to increase until the end of the test. After the coal sample permeability change over the previous anti-change changes gently.