Insight into the Creep Damage Evolution in Water-Immersed Coal Pillars: Experiment and Numerical Model Investigation

Coal mine underground reservoirs play a significant role in energy utilization while also contributing to energy security. Prolonged immersion in mine water reduces the long-term strength of coal, subsequently leading to continuous creep damage in coal pillars. This manifests as the propagation of d...

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Main Authors: Xueliang Li, Sihai Yi, Zheng Chen, Qingbiao Guo, Xiangjun Cai, Xin Guo, Haiyang Yi
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/18/13/3340
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author Xueliang Li
Sihai Yi
Zheng Chen
Qingbiao Guo
Xiangjun Cai
Xin Guo
Haiyang Yi
author_facet Xueliang Li
Sihai Yi
Zheng Chen
Qingbiao Guo
Xiangjun Cai
Xin Guo
Haiyang Yi
author_sort Xueliang Li
collection DOAJ
description Coal mine underground reservoirs play a significant role in energy utilization while also contributing to energy security. Prolonged immersion in mine water reduces the long-term strength of coal, subsequently leading to continuous creep damage in coal pillars. This manifests as the propagation of damage, ultimately resulting in instability, which affects their load-bearing capacity and impermeability. A multi-faceted approach involving laboratory experiments, similar model tests, and numerical simulations was employed to investigate the mechanical properties of water-immersed coal and the continuous creep damage process in coal pillars. Key findings reveal that water immersion significantly diminishes the long-term strength of coal; for example, initial instantaneous strain rose from 0.16% (non-immersed) to 0.25% (8-week immersion), with final creep strain reaching 1.15% versus 0.78%, respectively. The combined modeling methods effectively replicated the creep damage process, demonstrating that when concentrated stress exceeds the reduced long-term strength of coal, damage propagates toward the center of the pillar, forming continuous creep damage extending approximately 3.8 m within 7 years. This study contributes to our understanding of the creep damage mechanism in coal pillars and supports the long-term stability evaluation of CMURs.
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spelling doaj-art-52a95698b4dd4f5580e680ba8471edd02025-08-20T03:16:42ZengMDPI AGEnergies1996-10732025-06-011813334010.3390/en18133340Insight into the Creep Damage Evolution in Water-Immersed Coal Pillars: Experiment and Numerical Model InvestigationXueliang Li0Sihai Yi1Zheng Chen2Qingbiao Guo3Xiangjun Cai4Xin Guo5Haiyang Yi6Beijing Tianma Intelligent Control Technology Co., Ltd., Beijing 101399, ChinaSchool of Safety Engineering, North China Institute of Science and Technology, Langfang 065201, ChinaSchool of Mine Safety, North China Institute of Science and Technology, Langfang 065201, ChinaSchool of Geomatics, Anhui University of Science and Technology, Huainan 232001, ChinaKailuan Energy Chemical Co., Ltd., Tangshan 063100, ChinaThe Urban and Rural Planning Service Center of Yuncheng County, Heze 274799, ChinaSchool of Mine Safety, North China Institute of Science and Technology, Langfang 065201, ChinaCoal mine underground reservoirs play a significant role in energy utilization while also contributing to energy security. Prolonged immersion in mine water reduces the long-term strength of coal, subsequently leading to continuous creep damage in coal pillars. This manifests as the propagation of damage, ultimately resulting in instability, which affects their load-bearing capacity and impermeability. A multi-faceted approach involving laboratory experiments, similar model tests, and numerical simulations was employed to investigate the mechanical properties of water-immersed coal and the continuous creep damage process in coal pillars. Key findings reveal that water immersion significantly diminishes the long-term strength of coal; for example, initial instantaneous strain rose from 0.16% (non-immersed) to 0.25% (8-week immersion), with final creep strain reaching 1.15% versus 0.78%, respectively. The combined modeling methods effectively replicated the creep damage process, demonstrating that when concentrated stress exceeds the reduced long-term strength of coal, damage propagates toward the center of the pillar, forming continuous creep damage extending approximately 3.8 m within 7 years. This study contributes to our understanding of the creep damage mechanism in coal pillars and supports the long-term stability evaluation of CMURs.https://www.mdpi.com/1996-1073/18/13/3340coal pillarunderground water reservoirdamage propagationsimilar modelcreep damage
spellingShingle Xueliang Li
Sihai Yi
Zheng Chen
Qingbiao Guo
Xiangjun Cai
Xin Guo
Haiyang Yi
Insight into the Creep Damage Evolution in Water-Immersed Coal Pillars: Experiment and Numerical Model Investigation
Energies
coal pillar
underground water reservoir
damage propagation
similar model
creep damage
title Insight into the Creep Damage Evolution in Water-Immersed Coal Pillars: Experiment and Numerical Model Investigation
title_full Insight into the Creep Damage Evolution in Water-Immersed Coal Pillars: Experiment and Numerical Model Investigation
title_fullStr Insight into the Creep Damage Evolution in Water-Immersed Coal Pillars: Experiment and Numerical Model Investigation
title_full_unstemmed Insight into the Creep Damage Evolution in Water-Immersed Coal Pillars: Experiment and Numerical Model Investigation
title_short Insight into the Creep Damage Evolution in Water-Immersed Coal Pillars: Experiment and Numerical Model Investigation
title_sort insight into the creep damage evolution in water immersed coal pillars experiment and numerical model investigation
topic coal pillar
underground water reservoir
damage propagation
similar model
creep damage
url https://www.mdpi.com/1996-1073/18/13/3340
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AT zhengchen insightintothecreepdamageevolutioninwaterimmersedcoalpillarsexperimentandnumericalmodelinvestigation
AT qingbiaoguo insightintothecreepdamageevolutioninwaterimmersedcoalpillarsexperimentandnumericalmodelinvestigation
AT xiangjuncai insightintothecreepdamageevolutioninwaterimmersedcoalpillarsexperimentandnumericalmodelinvestigation
AT xinguo insightintothecreepdamageevolutioninwaterimmersedcoalpillarsexperimentandnumericalmodelinvestigation
AT haiyangyi insightintothecreepdamageevolutioninwaterimmersedcoalpillarsexperimentandnumericalmodelinvestigation