低透气性原煤瓦斯渗流各向异性试验研究
Experiment research on gas seepage anisotropy in low-permeability coal
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摘要: 为研究低透气性煤层中瓦斯渗流的各向异性,以同一煤岩平行层理方向和垂直层理方向制取煤样,利用自主研制的试验装置进行含瓦斯煤三轴伺服渗流试验.结果发现平行层理煤样的渗透率远大于垂直层理煤样.在峰值破坏前,平行层理煤样随着轴压增加,渗透率在应力屈服点达到最小值,垂直层理煤样在弹性阶段初始时达到最小值;峰值破坏后,两个方向煤样的渗透率均呈非线性增长.Abstract: To study the anisotropy of gas seepage in coal seams with low permeability,coal samples were prepared respectively in the parallel bedding direction and the vertical stratification direction of the same coal rock. Tri-axial servo seepage tests on gascontained coal were detected by using a self-developed apparatus. It is found that the permeability of coal samples in the parallel is far greater than that of coal samples in the vertical. With the increase of axial pressure,the permeability of coal samples in the parallel reaches its minimum at the yield point before the peak failure,while the permeability of coal samples in the vertical gets its minimum at the initial period of the elastic stage. The permeability of both the parallel and the vertical nonlinearly increases after the peak failure.