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利用MTS815Flex Test GT岩石力学试验系统,对平煤集团八矿的原煤和型煤试件进行渗流试验,对两种试件的力学和渗透特性进行了探讨.研究表明:原煤和型煤的力学特性相差较大,原煤强度高于型煤,但其变形特征却低于型煤,瓦斯压力会导致煤岩强度降低;煤体内裂纹的发生和发展直接影响煤岩的渗透特性,瓦斯渗透率-轴向应变曲线的渗透性变化转折点与煤体的变形具有良好的对应关系,原煤的渗透试验更能反映实际情况.渗透率由可压缩平行线性达西公式计算得到,在相同瓦斯压力下,煤岩的渗透率变化规律与流量变化规律相同,在不同瓦斯压力下,随着瓦斯压力升高,流量逐渐增大,而渗透率逐渐减小,这是由于煤岩破坏后,其内部形成宏观裂纹面,瓦斯气体主要沿该裂纹面渗透,此时可压缩平行线性达西公式已不能完全表征煤岩渗透性.
Using the MTS815Flex Test GT rock mechanics test system, the seepage test was carried out on the coal and briquette samples of Pingmei Group VIII, and the mechanical and permeability characteristics of the two samples were discussed. The results show that the mechanical properties of raw coal and briquette But the deformation characteristics are lower than those of briquette. The gas pressure will cause the strength of coal and rock to decrease. The occurrence and development of cracks in coal directly affect the permeability characteristics of coal and rock, and the permeability of gas-axis The turning point of the permeability curve to the strain curve has a good correspondence with the deformation of the coal body, and the permeability test of raw coal better reflects the actual situation.The permeability is calculated from the compressible parallel Darcy formula, and under the same gas pressure, Permeability changes with the same flow pattern, with different gas pressure, with the gas pressure increases, the flow increases gradually, while the permeability decreases gradually, which is due to the destruction of coal and rock, the formation of its internal macro-crack surface , The gas mainly permeates along the crack surface. At this time, the compressible parallel Darcy formula can not completely characterize the permeability of coal and rock.