Deformation and permeability model of coal and rock considering moisture content

被引:0
作者
Li B. [1 ,2 ,3 ]
Li J. [1 ]
Yang K. [1 ]
Ren C. [1 ]
Xu J. [4 ]
Zhang M. [4 ]
机构
[1] College of Mining, Guizhou University, Guiyang
[2] The National Joint Engineering Laboratory for the Utilization of Dominant Mineral Resources in Karst Mountain Area, Guiyang
[3] State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao
[4] State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing
来源
Meitan Xuebao/Journal of the China Coal Society | 2019年 / 44卷 / 04期
关键词
Coal; Deformation; Permeability; Pore pressure; Water content;
D O I
10.13225/j.cnki.jccs.2018.0608
中图分类号
学科分类号
摘要
The depth of coal mining is increasing, and the increase of gas content in coal seams leads to the gradual increase of dynamic disasters, which brings severe challenges to the safe production of coal mines. Research on the flow of gas in coal seams has always been a concern and the permeability is one of the key parameters affecting gas flow in coal seams. With the application of the coal containing gas heat-fluid-solid coupling device of three axis servo seepage, it can simulate the deformation and seepage characteristics of coal mining caused by the environment through the experimental studies on the permeability of the process of the coal when the pore pressure are under different saturated conditions. Then considering moisture content, the authors establishes an adsorption equation and adsorption-permeability model so as to model the common effect of water content and pore pressure on the deformation and permeability characteristics of coal. The results show that: ① in the process of pore pressure increase, the radial strain and axial strain decrease with the pore pressure increases, and the change of gas flow increases. Due to gas adsorption, coal matrix swells, and the volumetric strain decreases gradually. ② When the water content is constant, and with the increase of pore pressure, the gas adsorption capacity increases first and then levels off. The coal gas adsorption capacity and deformation decrease with the increase in moisture content when the pore pressure is constant. ③ Under constant moisture conditions, coal permeability curve decreases first and then levels off with the pore pressure increase. Under a constant pore pressure, with the increase of moisture content of coal, the permeability decreases gradually, the higher moisture content of pore pressure, the less effect on the permeability by pore pressure, the stronger effect on permeability by water molecules. ④ The calculation formula of the adsorption amount considering the water content is constructed, and on this basis, the coal adsorption-permeability model considering the water content is further constructed. The calculated permeability value is basically consistent with the experimental results, which reflects the variation law of coal permeability. © 2019, Editorial Office of Journal of China Coal Society. All right reserved.
引用
收藏
页码:1076 / 1083
页数:7
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