Geomechanics and Engineering

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Mechanical deterioration and thermal deformations of high-temperature-treated coal with evaluations by EMR

  • Biao, Kong (College of Safety and Environmental Engineering, Shandong University of Science and Technology) ;
  • Sixiang, Zhu (College of Safety and Environmental Engineering, Shandong University of Science and Technology) ;
  • Wenrui, Zhang (College of Safety and Environmental Engineering, Shandong University of Science and Technology) ;
  • Xiaolei, Sun (College of Safety and Environmental Engineering, Shandong University of Science and Technology) ;
  • Wei, Lu (College of Safety and Environmental Engineering, Shandong University of Science and Technology) ;
  • Yankun, Ma (Engineering Technology Research Centre for Safe and Efficient Coal Mining (Anhui University of Science and Technology))
  • Received : 2020.11.06
  • Accepted : 2023.01.11
  • Published : 2023.01.25
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Abstract

With the increasing amount of resources required by the society development, mining operations go deeper, which raises the requirements of studying the effects of temperature on the physical and mechanical properties of coal and adjacent rock. For now, these effects are yet to be fully revealed. In this paper, a mechanical-electromagnetic radiation (EMR) test system was established to understand the mechanical deterioration characteristics of coal by the effect of thermal treatment and its deformation and fracture characteristics under thermo-mechanical coupling conditions. The mechanical properties of high-temperature-treated coal were analyzed and recorded, based on which, reasons of coal mechanical deterioration as well as the damage parameters were obtained. Changes of the EMR time series under unconstrained conditions were further analyzed before characteristics of EMR signals under different damage conditions were obtained. The evolution process of thermal damage and deformation of coal was then analyzed through the frequency spectrum of EMR. In the end, based on the time-frequency variation characteristics of EMR, a method of determining combustion zones within the underground gasification area and combustion zones' stability level was proposed.

Keywords

Acknowledgement

The research described in this paper was financially supported by the National Natural Science Foundation of China (51904172, 51974178), the China Postdoctoral Science Foundation (2020M682209), the Open Project Funding of the State Key Laboratory of Coal Mine Safety Technology (CCTEG-Shenyang-Research-Institute) (2022-KF-23-02), the Open Project Funding of Scientific Research and Development Platform of Technology of Disaster Prevention in Deep Coal Mines(SECM2202), the Qingdao West Coast New Area Science and Technology Benefiting People Project(2019-109)..

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