Deterioration evolution mechanism and damage constitutive model improvement of sandstone–coal composite samples under the effect of repeated immersion

IR (HANDLE) Open Access
  • Jiang, Tianqi
    Department of Earth Resources Engineering, Kyushu University
  • Zhu, Chun
    School of Earth Sciences and Engineering, Hohai University
  • Qiao, Yang
    Oulu Mining School, University of Oulu College of Civil Engineering, Tongji University
  • Sasaoka, Takashi
    Department of Earth Resources Engineering, Kyushu University
  • Shimada, Hideki
    Department of Earth Resources Engineering, Kyushu University
  • Hamanaka, Akihiro
    Department of Earth Resources Engineering, Kyushu University
  • Li, Wei
    State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, China University of Mining and Technology
  • Chen, Bingbing
    Zienkiewicz Institute for Modelling, Data and AI, Faculty of Science and Engineering, Swansea University

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Description

Underground reservoirs in coal mines, consisting of goafs (By goaf, we mean the space that remains underground after the extraction of valuable minerals), are commonly utilized for mine water storage and drainage, with their primary load-bearing structures being the “roof–coal pillar” systems. Consequently, this structure must endure the repeated immersion behavior resulting from fluctuations in the mine water level, resulting in the risk of geological disasters. This paper analyzes the variation in mechanical properties of sandstone–coal composite samples after repeated immersion cycles through axial loading tests. The results indicate that the water content of the sample exhibits a notable and rapid increase with each successive immersion cycle. This corresponds to a decrease in the stress threshold and modulus parameters of the samples. Moreover, the acoustic emission signals serve as indicators of the softening characteristics of the samples. With the increase in immersion cycles, there is an augmentation in both the frequency and extent of shear cracks. The non-linear failure characteristics of the samples become more pronounced. Consequently, water significantly weakens the cementing material between rock grains. Both sandstone and coal display a decrease in deformation resistance capabilities at a macroscopic level. The constitutive model of the composite sample was improved based on the degradation characteristics of mechanical strength and strain energy parameters, which offers enhanced accuracy in analyzing the degradation process caused by water immersion. This paper offers a crucial theoretical foundation for comprehending the deterioration evolution characteristics of the “roof–coal pillar” bearing structure affected by repeated immersion.

Journal

  • Physics of Fluids

    Physics of Fluids 36 (5), 056611-1-056611-17, 2024-05-16

    AIP Publishing

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Details 詳細情報について

  • CRID
    1050867278048674048
  • NII Book ID
    AA10986202
  • ISSN
    10897666
    10706631
  • HANDLE
    2324/7236776
  • Text Lang
    en
  • Article Type
    journal article
  • Data Source
    • IRDB

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