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ORIGINAL RESEARCH article

Front. Earth Sci.
Sec. Geoscience and Society
Volume 12 - 2024 | doi: 10.3389/feart.2024.1445254
This article is part of the Research Topic Exploration, Development, and Protection of Earth’s Resources and Environment: Methods, Techniques, Applications, Prospects, Insights, and Problems View all 11 articles

Effect of stress unloading rate on fine-scale deformation mechanism of rock under high osmotic pressure

Provisionally accepted
Weiji Sun Weiji Sun 1Qin XU Qin XU 1Qiang Liu Qiang Liu 1*Yujun Zhang Yujun Zhang 2Wenfei Ma Wenfei Ma 1Yangqi Ma Yangqi Ma 1Jingang Gao Jingang Gao 3
  • 1 Liaoning Technical University, Fuxin, China
  • 2 CCTEG Shenyang Research Institute, Beijing, Beijing Municipality, China
  • 3 CCTEG Shenyang Research Institute, Fushun, China

The final, formatted version of the article will be published soon.

    To explore the influence of the working face excavation rate on the rock deformation mechanism and seepage characteristics, deformation and seepage tests of sandstone under different loading and unloading stress paths, such as constant axial pressure unloading confining pressure and loading axial pressure unloading confining pressure, were carried out. Particle Flow Code in 3 Dimensions (PFC 3D ) and Python were used to realize fluid-solid coupling, and numerical simulation calculations were performed along the test path to analyze the influence of the unloading rate on the fine-scale deformation mechanism and permeability characteristics of sandstone, and the relationship between crack type and permeability was obtained. A sandstone fracture mechanics model is established to analyze the stress concentration degree at the end of the branch crack of the test path. The results show that the rate of confining pressure unloading is inversely proportional to the strain. Additionally, permeability correlates with the principal stress difference in an exponential manner. Interestingly, the sensitivity of permeability to stress shows an inverse trend with the unloading rate of confining pressure. Furthermore, there exists a linear relationship between permeability and the number of cracks. During the unloading process, tensile cracks predominate, and the propagation of shear cracks lags behind that of tensile cracks. The proportion of tensile cracks decreases with the increase of the unloading rate when the axial pressure is unchanged but increases when axial pressure is added, resulting in axial compression deformation and expansion deformation along the unloading direction. These research outcomes offer theoretical insights for the prudent selection of mining rates, and they hold significant implications for mitigating water inrush disasters in deep mining operations.

    Keywords: Unloading rate, Fluid-solid coupling, Permeability, Cracks, deformation

    Received: 07 Jun 2024; Accepted: 18 Jul 2024.

    Copyright: © 2024 Sun, XU, Liu, Zhang, Ma, Ma and Gao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Qiang Liu, Liaoning Technical University, Fuxin, China

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