首页|Experimental and theoretical study on the dynamic effective stress of loaded gassy coal during gas release

Experimental and theoretical study on the dynamic effective stress of loaded gassy coal during gas release

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In the process of mining coalbed methane(CBM),an unsteady state often arises due to the rapid extrac-tion,release and pressure relief of CBM.In this case,the effective stress of coal changes dynamically,affecting the stability of the gassy coal seam.In this paper,gas release tests of gassy coal under conven-tional triaxial compression were performed,and the dynamic effective stress(DES)during gas release was obtained indirectly based on a constitutive equation and deformation of coal.The results show that the maximum increases in DES caused by the release of free gas and adsorbed gas under the stress of 1.1 MPa were 0.811 and 5.418 MPa,respectively,which seriously affected the stress state of the coal.During the gas release,the free gas pressure and the adsorbed gas volume were the parameters that directly affected the DES and showed a positive linear relationship with the DES with an intercept of zero.The DES of the coal sample increased exponentially with time,which was determined by the contents of free and adsorbed gas.Based on the experimental results and theoretical analysis,an effective stress model was obtained for loaded gassy coal during gas release.The results of verification indicated accu-racy greater than 99%.

Gassy coalDynamic effective stressGas releaseGas-solid couplingMathematical model

Bing Zhang、Hanpeng Wang、Peng Wang、Guofeng Yu、Shitan Gu

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School of Qilu Transportation,Shandong University,Jinan 250061,China

Geotechnical and Structural Engineering Research Center,Shandong University,Jinan 250061,China

Coal Mining National Engineering Technology Research Institute,Huainan 232001,China

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 266590,China

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National Natural Science Foundation of ChinaChina Postdoctoral Science FoundationPostdoctoral Innovation Project of Shandong ProvinceNatural Science Foundation of Shandong Province

521740812021M7020012021020022019GSF111036

2023

矿业科学技术学报(英文版)
中国矿业大学

矿业科学技术学报(英文版)

CSTPCDCSCD北大核心EI
影响因子:1.222
ISSN:2095-2686
年,卷(期):2023.33(3)
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