承压破碎煤体渗透特性参数演化实验研究

发布时间：2018-07-10 02:28

本文选题：采空区 + 承压　；参考：《煤炭学报》2017年04期

【摘要】：为研究承压破碎煤体渗透特性参数演化规律,利用自主设计的承压破碎遗煤渗透率演化实验装置,开展了不同粒径配比煤样在不同轴压下的渗透率演化实验。实验结果表明:(1)在相同应力作用下,随着煤样粒径的增大,其渗透率逐渐变小,且较大粒径范围煤样的渗透率较小;在应力增加量相同的条件下,随着煤样粒径的增大,其渗透率的变化率越大,且混合粒径范围较大煤样渗透率的变化率均高于单一粒径或粒径范围小的煤样的变化率。(2)在较低孔隙压力范围内,煤样的渗透率均随孔隙压力的增大呈现出降低趋势,且存在一个轴压的临界值(9 MPa左右)。当轴压小于该临界值时,随着孔隙压力的增加,煤样渗透率的变化趋势更明显;而当轴压大于该临界值时,煤样渗透率的变化趋势较为平缓。(3)加载初期,随着孔隙率的减小,渗透率近似线性下降;当轴压达到9~12 MPa时,渗透率随孔隙率的下降较为平缓;继续增加轴压,渗透率随孔隙率的减小而急剧降低。
[Abstract]:In order to study the evolution law of the permeability characteristic parameters of the crushed coal body, the permeability evolution experiment of coal samples with different particle size ratio under different axial compression is carried out by using the independent design of pressure broken coal permeability evolution experiment device. The experimental results show that: (1) under the action of the same stress, the permeability gradually changes with the increase of the coal sample size. The permeability of coal samples with small size and larger particle size is smaller. With the same stress increase, the permeability change is greater with the increase of coal particle size, and the change rate of coal sample permeability is higher than that of single particle size or small size. (2) coal in the range of lower pore pressure. The permeability of the sample decreases with the increase of pore pressure, and there is a critical value of axial pressure (about 9 MPa). When the axial pressure is less than the critical value, with the increase of pore pressure, the change trend of coal permeability is more obvious; and when the axial pressure is greater than the critical value, the change trend of coal sample permeability is relatively gentle. (3) initial loading With the decrease of porosity, the permeability decreases approximately linearly. When the axial pressure reaches 9~12 MPa, the permeability decreases with the porosity, and the axial pressure continues to increase, and the permeability decreases sharply with the decrease of porosity.
【作者单位】：河南理工大学安全科学与工程学院;重庆大学煤矿灾害动力学与控制国家重点实验室;
【基金】：国家自然科学基金资助项目(U1361205,51404090,51574111)
【分类号】：TD752.2

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