The effect of gas migration on the deformation and permeability of coal under the condition of true triaxial stress

  • Gang WangEmail author
  • Zhiyuan Liu
  • Pengfei Wang
  • Yangyang Guo
  • Wenrui Wang
  • Tengyao Huang
  • Wenxin Li
Original Paper


The dynamic characteristics of gas flow are often not considered in a true triaxial stress environment, making the simulation test hard to meet the requirement for coal and gas outburst in reality. To solve this issue, we investigated the deformation and gas flow characteristics of coal-like briquette under true triaxial stress conditions using self-developed triaxial servo-controlled seepage equipment for fluid-solid coupling of coal containing methane. Analysis of the experimental data revealed the relationship of coal body’s stress to strain as well as the relationship of their permeability. The results showed that in the conventional triaxial and true triaxial compression seepage tests, the relationship of stress-strain-permeability varies at different stages. The stress-strain curves in the whole stress-strain process of coal show a trend of decrease after increase, while the permeability-strain curves show a trend of increase after decrease. There is a “stress-sensitive zone” in the influence of the intermediate principal stress on the minimum permeability of the coal. The gas pressure promotes the “fluctuation” strain of the coal body, resulting in an instantaneous increase in the strain rate. The research provides the experimental basis for studying the permeability of coal body in the true triaxial stress environment.


Coal mine methane drainage True triaxial test Intermediate principal stress Gas pressure Permeability 


Funding information

This study was financially supported by the National Natural Science Foundation of China (project no. 51604168, 51474106), the Open Fund of Hebei State Key Laboratory of Mine Disaster Prevention (project no. KJZH2017K10), the Program for the Outstanding Young Scientists of Shandong University of Science and Technology (project no. 2015JQJH105), the Taishan Scholar Talent Team Support Plan for Advantaged and Unique Discipline Areas, and the Source Innovation Program (Applied Research Special—Youth Special) of Qingdao (project no. 17-1-1-38-jch).


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Copyright information

© Saudi Society for Geosciences 2019

Authors and Affiliations

  • Gang Wang
    • 1
    • 2
    • 3
    Email author
  • Zhiyuan Liu
    • 2
  • Pengfei Wang
    • 2
  • Yangyang Guo
    • 2
  • Wenrui Wang
    • 2
  • Tengyao Huang
    • 2
  • Wenxin Li
    • 2
  1. 1.Mine Disaster Prevention and Control-Ministry of State Key Laboratory Breeding BaseShandong University of Science and TechnologyQingdaoChina
  2. 2.College of Mining and Safety EngineeringShandong University of Science and TechnologyQingdaoChina
  3. 3.Hebei State Key Laboratory of Mine Disaster PreventionNorth China Institute of Science and TechnologyBeijingChina

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