负压条件下构造煤原煤样瓦斯渗透性实验

发布时间：2018-09-12 08:54

【摘要】：利用三轴应力渗流实验装置对坚固性系数为0.3的构造煤原煤煤样进行了加压破坏以及负压条件下含瓦斯构造煤原煤煤样的瓦斯渗透性实验研究。结果表明,坚固性系数为0.3的构造煤原煤样的压裂过程经历了非线性压密阶段、线弹性阶段、应变强化阶段、应力跌落阶段和应变软化阶段等5个阶段。在围压、瓦斯压力一定,同一轴压条件下,加载负压时的煤体瓦斯渗透率要大于不加载负压时的煤体瓦斯渗透率,随着负压增大瓦斯渗透率随之增大。在围压、瓦斯压力一定,同一负压条件下,随着轴压的增大,瓦斯渗透率先逐渐增大到一定峰值后逐渐减小。在围压、负压一定,同一轴压条件下,瓦斯压力越大,煤体的瓦斯渗透率越小。在围压、负压、瓦斯压力一定的条件下,轴压加载到σo值后,开始卸载轴压,随着轴压的卸载煤体瓦斯渗透率逐渐增大,在轴压卸载的初始阶段,渗透率增幅较大;随后在轴压卸载完全的过程中,渗透率的增幅越来越不明显,并且轴压卸载为0时的渗透率要小于煤样试件在加载轴压前的初始渗透率。
[Abstract]:Using triaxial stress seepage experimental apparatus, the pressure failure and gas permeability of raw coal samples of structural coal with 0.3 coefficient of firmness under negative pressure are studied. The results show that the fracturing process of raw coal samples of structural coal with 0.3 coefficient of firmness undergoes nonlinear compaction and linear elasticity. In the same axial pressure, the gas permeability under negative pressure is higher than that under no negative pressure, and the gas permeability increases with negative pressure. Under a negative pressure condition, with the increase of axial pressure, the gas permeability first increases to a certain peak value and then decreases gradually. Under a certain confining pressure and negative pressure, under the same axial pressure condition, the greater the gas pressure, the smaller the gas permeability. The gas permeability of the unloaded coal body under axial pressure increases gradually, and the permeability increases greatly at the initial stage of unloading under axial pressure; then the permeability increases less and less obviously during the complete process of unloading under axial pressure, and the permeability of the unloaded coal sample is less than the initial permeability of the coal sample before unloading under axial pressure.
【作者单位】：河南工程学院安全工程学院;武汉理工大学资源与环境工程学院;
【基金】：国家自然科学基金资助项目(51174082) “煤矿灾害预防与控制河南省高校重点实验室培育基地”建设资助项目河南工程学院科技创新团队建设资助项目(CXTD2014002)
【分类号】：TD712

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