Long-Term Creep Mechanical and Acoustic Emission Characteristics of Water-Immersed Coal Pillar Dam
This study conducted uniaxial creep tests on coal samples under both natural and water-saturated conditions for durations of about 180 days per sample to study the stability of coal pillar dams of the Daliuta Coal Mine underground reservoir. Combined with synchronized acoustic emission (AE) monitori...
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| Language: | English |
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MDPI AG
2025-07-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/15/14/8012 |
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| author | Ersheng Zha Mingbo Chi Zhiguo Cao Baoyang Wu Jianjun Hu Yan Zhu |
| author_facet | Ersheng Zha Mingbo Chi Zhiguo Cao Baoyang Wu Jianjun Hu Yan Zhu |
| author_sort | Ersheng Zha |
| collection | DOAJ |
| description | This study conducted uniaxial creep tests on coal samples under both natural and water-saturated conditions for durations of about 180 days per sample to study the stability of coal pillar dams of the Daliuta Coal Mine underground reservoir. Combined with synchronized acoustic emission (AE) monitoring, the research systematically revealed the time-dependent deformation mechanisms and damage evolution laws of coal under prolonged water immersion and natural conditions. The results indicate that water-immersed coal exhibits a unique negative creep phenomenon at the initial stage, with the strain rate down to −0.00086%/d, attributed to non-uniform pore compaction and elastic rebound effects. During the steady-state creep phase, the creep rates under water-immersed and natural conditions were comparable. However, water immersion led to an 11.4% attenuation in elastic modulus, decreasing from 2300 MPa to 2037 MPa. Water immersion would also suppress AE activity, leading to the average daily AE events of 128, which is only 25% of that under natural conditions. In the accelerating creep stage, the AE event rate surged abruptly, validating its potential as an early warning indicator for coal pillar instability. Based on the identified long-term strength of the coal sample, it is recommended to maintain operational loads below the threshold of 9 MPa. This research provides crucial theoretical foundations and experimental data for optimizing the design and safety monitoring of coal pillar dams in CMURs. |
| format | Article |
| id | doaj-art-226ea5d78bc24622b9ec6049ce6d86e0 |
| institution | Kabale University |
| issn | 2076-3417 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj-art-226ea5d78bc24622b9ec6049ce6d86e02025-08-20T03:36:13ZengMDPI AGApplied Sciences2076-34172025-07-011514801210.3390/app15148012Long-Term Creep Mechanical and Acoustic Emission Characteristics of Water-Immersed Coal Pillar DamErsheng Zha0Mingbo Chi1Zhiguo Cao2Baoyang Wu3Jianjun Hu4Yan Zhu5China Academy of Safety Science and Technology, Beijing 100012, ChinaChina Academy of Safety Science and Technology, Beijing 100012, ChinaState Key Laboratory of Water Resource Protection and Utilization in Coal Mining, Beijing 102299, ChinaState Key Laboratory of Water Resource Protection and Utilization in Coal Mining, Beijing 102299, ChinaState Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, Shenzhen University, Shenzhen 518060, ChinaChina Academy of Safety Science and Technology, Beijing 100012, ChinaThis study conducted uniaxial creep tests on coal samples under both natural and water-saturated conditions for durations of about 180 days per sample to study the stability of coal pillar dams of the Daliuta Coal Mine underground reservoir. Combined with synchronized acoustic emission (AE) monitoring, the research systematically revealed the time-dependent deformation mechanisms and damage evolution laws of coal under prolonged water immersion and natural conditions. The results indicate that water-immersed coal exhibits a unique negative creep phenomenon at the initial stage, with the strain rate down to −0.00086%/d, attributed to non-uniform pore compaction and elastic rebound effects. During the steady-state creep phase, the creep rates under water-immersed and natural conditions were comparable. However, water immersion led to an 11.4% attenuation in elastic modulus, decreasing from 2300 MPa to 2037 MPa. Water immersion would also suppress AE activity, leading to the average daily AE events of 128, which is only 25% of that under natural conditions. In the accelerating creep stage, the AE event rate surged abruptly, validating its potential as an early warning indicator for coal pillar instability. Based on the identified long-term strength of the coal sample, it is recommended to maintain operational loads below the threshold of 9 MPa. This research provides crucial theoretical foundations and experimental data for optimizing the design and safety monitoring of coal pillar dams in CMURs.https://www.mdpi.com/2076-3417/15/14/8012coal mine underground reservoirlong-term creep behavioracoustic emissionwater immersionstability analysis |
| spellingShingle | Ersheng Zha Mingbo Chi Zhiguo Cao Baoyang Wu Jianjun Hu Yan Zhu Long-Term Creep Mechanical and Acoustic Emission Characteristics of Water-Immersed Coal Pillar Dam Applied Sciences coal mine underground reservoir long-term creep behavior acoustic emission water immersion stability analysis |
| title | Long-Term Creep Mechanical and Acoustic Emission Characteristics of Water-Immersed Coal Pillar Dam |
| title_full | Long-Term Creep Mechanical and Acoustic Emission Characteristics of Water-Immersed Coal Pillar Dam |
| title_fullStr | Long-Term Creep Mechanical and Acoustic Emission Characteristics of Water-Immersed Coal Pillar Dam |
| title_full_unstemmed | Long-Term Creep Mechanical and Acoustic Emission Characteristics of Water-Immersed Coal Pillar Dam |
| title_short | Long-Term Creep Mechanical and Acoustic Emission Characteristics of Water-Immersed Coal Pillar Dam |
| title_sort | long term creep mechanical and acoustic emission characteristics of water immersed coal pillar dam |
| topic | coal mine underground reservoir long-term creep behavior acoustic emission water immersion stability analysis |
| url | https://www.mdpi.com/2076-3417/15/14/8012 |
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