煤岩全应力应变过程渗透性特征试验研究

Test study on permeability properties of coal specimen in complete stress-strain process

在MTS815岩石伺服试验机上进行了煤岩全应力-应变过程中的渗透性试验,揭示了煤岩在变形破坏过程中的渗透率变化规律。试验结果表明,应变-渗透率曲线与应力-应变曲线变化趋势基本一致,但表现出相对“滞后”的特点,表明渗透率的变化与其损伤演化过程密切相关,同时煤体通过其内部裂隙的渗透需要一定的时间过程。同其他沉积岩石相比,煤岩微结构及微组分复杂多样,不同煤岩类型其渗透率相差很大。同时,由于煤岩微孔隙裂隙相对较发育,其渗透率受有效围压的影响更明显。

The permeability test of coal in the complete stress-strain process is carried on the MTS815 Servo-controlled Rock Mechanical Test System. Test results indicate that the permeability rate curve and the complete stress-strain curve of coal almost have the same variation trend. But the permeability rate-strain curve is relatively ＂hysteretic＂ which indicates that the close relativity between the evolvement of damage and the development of permeability rate and the permeability developing needs a time. The micro-structure and micro-composition of coal are more complicated and different than other sedimentary rocks; so the permeability of different kinds of coal is much different. Moreover, the micro-porosity and micro-fracture of coal are more developed, so the influence of available confining pressure on penetrability of coal is more obviously.