冲击载荷下各向异性煤体渗透-应力敏感性试验研究*

为揭示冲击煤样渗透率的变化规律，通过立式分离式霍普金森（SHPB）冲击装置对不同层理方向煤样进行动态冲击，进而采用渗透仪对冲击后的煤样进行渗透率测试，分析不同冲击荷载下煤岩的渗透率及应力敏感性。结果表明:冲击煤样的渗透率远大于原煤样品，冲击载荷越大，渗透率越大；在相同的冲击载荷和气体压力下，平行于层理方向的煤样渗透率最大，其次是斜交45°层理方向的煤样渗透率，垂直于层理方向的煤样渗透率最小；渗透率受有效应力影响显著；在冲击荷载的作用下，垂直于层理方向煤样渗透率的变化率对孔隙压力更为敏感。

Experimental study on permeability and stress sensitivity of anisotropic coal under impact load

In order to reveal the variation law of coal permeability under impact load,the vertical split Hopkinson (SHPB) impact device was used to conduct dynamic impact on coal samples with different bedding directions,and then the permeability of coal samples after impact was tested by permeability instrument,and the permeability and stress sensitivity of coal and rock under different impact loads were analyzed.The results showed that the permeability of impacted coal sample was much larger than that of raw coal sample,and the greater the impact load,the greater the permeability.Under the same impact load and gas pressure,the permeability of coal sample being parallel to bedding direction was the largest,followed by the coal sample being 45° oblique to bedding direction,and the permeability of coal sample being perpendicular to bedding direction was the lowest.The permeability was significantly affected by the effective stress.Under the effect of impact load,the permeability change rate of coal sample being perpendicular to bedding direction was more sensitive to the pore pressure.