多因素对煤体渗透率影响的试验研究

Experimental Study on Influence of Multiple Factors on Coal Permeability

为了探讨煤体渗透率的影响因素,利用损伤煤岩体渗流试验系统,进行了不同轴压、围压和瓦斯压力下煤体渗透率的渗流试验。试验结果表明:煤样在相同围压条件下时,渗透率与轴压的关系符合二次多项式函数;煤样在相同轴压条件下时,渗透率与围压的关系符合幂函数;在相同应力情况下,煤样的渗透率随瓦斯压力的升高先降低后升高,呈现"V"字形变化趋势,煤样的临界瓦斯压力值随煤样应力值的增大而增大;煤样轴向渗流的渗透率对围压的敏感性远大于轴压,渗透率对围压的敏感性大约是对轴压的敏感性的8.5倍。

In order to explore the influencing factors of coal permeability,the seepage test of coal permeability under different axial pressure,confining pressure and gas pressure was carried out by using the seepage test system of damaged coal-rock mass.The test results show that under the same confining pressure,the relation between permeability and axial pressure is quadratic polynomial function;the relation between permeability and confining pressure of coal samples under coaxial pressure conditions conforms to power function;under the same stress condition,the permeability of coal sample first decreases and then increases with the increase of gas pressure,showing a V-shaped change trend,and the critical gas pressure value of coal sample increases with the increase of coal stress value;the permeability of coal axial seepage is more sensitive to confining pressure than axial pressure,the sensitivity of permeability to confining pressure is about 8.5 times that of axial pressure.