Prediction of Fracture Evolution and Groundwater Inrush from Karst Collapse Pillars in Coal Seam Floors: A Micromechanics-Based Stress-Seepage-Damage Coupled Modeling Approach
Karst collapse pillars (KCPs) frequently cause severe groundwater inrush disasters in coal mining above a confined aquifer. An accurate understanding of the damage and fracture evolution, permeability enhancement, and seepage changes in KCPs under the combined action of mining-induced stress and con...
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| Format: | Article |
| Language: | English |
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Wiley
2020-01-01
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| Series: | Geofluids |
| Online Access: | http://dx.doi.org/10.1155/2020/8830304 |
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| author | Yinlong Lu Bingzhen Wu Mengqi He Lianguo Wang Dan Ma Zhen Huang |
| author_facet | Yinlong Lu Bingzhen Wu Mengqi He Lianguo Wang Dan Ma Zhen Huang |
| author_sort | Yinlong Lu |
| collection | DOAJ |
| description | Karst collapse pillars (KCPs) frequently cause severe groundwater inrush disasters in coal mining above a confined aquifer. An accurate understanding of the damage and fracture evolution, permeability enhancement, and seepage changes in KCPs under the combined action of mining-induced stress and confined hydraulic pressure is of great significance for the early prediction and prevention of groundwater inrush from KCPs in coal seam floors. In this study, a micromechanics-based coupled stress-seepage-damage (SSD) modeling approach, in which the macroscopic mechanical and hydraulic properties of the rock are explicitly related to the microcrack kinetics, is proposed to simulate the fracture evolution and the associated groundwater flow in KCPs. An in situ high-precision microseismic monitoring technology is used to verify the micromechanical modeling results, which indicate that the numerical model successfully reproduces the damage and fracture evolution in a coal seam floor with a KCP during the mining process. The presented model also provides a visual representation of the complex process of KCP activation and groundwater inrush channel formation. A numerical study shows that the damage and activation of a KCP start from the edge of the KCP, gradually develop toward the interior of the KCP, and eventually connect with the damage fracture zone of the floor, forming a primary water-conducting channel in the KCP, causing the confined groundwater to flow into the working face. Groundwater inrush from a KCP is a gradual process instead of a mutation process. A reduction in the distance between the working face and a KCP and increases in the confined hydraulic pressure and the initial water-conducting height of the KCP can significantly increase the risk of groundwater inrush from the KCP. |
| format | Article |
| id | doaj-art-28eeca0ab48843fa8498a9e62ae884e7 |
| institution | Kabale University |
| issn | 1468-8115 1468-8123 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geofluids |
| spelling | doaj-art-28eeca0ab48843fa8498a9e62ae884e72025-02-03T01:03:40ZengWileyGeofluids1468-81151468-81232020-01-01202010.1155/2020/88303048830304Prediction of Fracture Evolution and Groundwater Inrush from Karst Collapse Pillars in Coal Seam Floors: A Micromechanics-Based Stress-Seepage-Damage Coupled Modeling ApproachYinlong Lu0Bingzhen Wu1Mengqi He2Lianguo Wang3Dan Ma4Zhen Huang5State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116, ChinaState Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116, ChinaState Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116, ChinaState Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116, ChinaState Key Laboratory of Coal Resources and Safe Mining, School of Mines, China University of Mining and Technology, Xuzhou, Jiangsu 221116, ChinaSchool of Resources and Environment Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, ChinaKarst collapse pillars (KCPs) frequently cause severe groundwater inrush disasters in coal mining above a confined aquifer. An accurate understanding of the damage and fracture evolution, permeability enhancement, and seepage changes in KCPs under the combined action of mining-induced stress and confined hydraulic pressure is of great significance for the early prediction and prevention of groundwater inrush from KCPs in coal seam floors. In this study, a micromechanics-based coupled stress-seepage-damage (SSD) modeling approach, in which the macroscopic mechanical and hydraulic properties of the rock are explicitly related to the microcrack kinetics, is proposed to simulate the fracture evolution and the associated groundwater flow in KCPs. An in situ high-precision microseismic monitoring technology is used to verify the micromechanical modeling results, which indicate that the numerical model successfully reproduces the damage and fracture evolution in a coal seam floor with a KCP during the mining process. The presented model also provides a visual representation of the complex process of KCP activation and groundwater inrush channel formation. A numerical study shows that the damage and activation of a KCP start from the edge of the KCP, gradually develop toward the interior of the KCP, and eventually connect with the damage fracture zone of the floor, forming a primary water-conducting channel in the KCP, causing the confined groundwater to flow into the working face. Groundwater inrush from a KCP is a gradual process instead of a mutation process. A reduction in the distance between the working face and a KCP and increases in the confined hydraulic pressure and the initial water-conducting height of the KCP can significantly increase the risk of groundwater inrush from the KCP.http://dx.doi.org/10.1155/2020/8830304 |
| spellingShingle | Yinlong Lu Bingzhen Wu Mengqi He Lianguo Wang Dan Ma Zhen Huang Prediction of Fracture Evolution and Groundwater Inrush from Karst Collapse Pillars in Coal Seam Floors: A Micromechanics-Based Stress-Seepage-Damage Coupled Modeling Approach Geofluids |
| title | Prediction of Fracture Evolution and Groundwater Inrush from Karst Collapse Pillars in Coal Seam Floors: A Micromechanics-Based Stress-Seepage-Damage Coupled Modeling Approach |
| title_full | Prediction of Fracture Evolution and Groundwater Inrush from Karst Collapse Pillars in Coal Seam Floors: A Micromechanics-Based Stress-Seepage-Damage Coupled Modeling Approach |
| title_fullStr | Prediction of Fracture Evolution and Groundwater Inrush from Karst Collapse Pillars in Coal Seam Floors: A Micromechanics-Based Stress-Seepage-Damage Coupled Modeling Approach |
| title_full_unstemmed | Prediction of Fracture Evolution and Groundwater Inrush from Karst Collapse Pillars in Coal Seam Floors: A Micromechanics-Based Stress-Seepage-Damage Coupled Modeling Approach |
| title_short | Prediction of Fracture Evolution and Groundwater Inrush from Karst Collapse Pillars in Coal Seam Floors: A Micromechanics-Based Stress-Seepage-Damage Coupled Modeling Approach |
| title_sort | prediction of fracture evolution and groundwater inrush from karst collapse pillars in coal seam floors a micromechanics based stress seepage damage coupled modeling approach |
| url | http://dx.doi.org/10.1155/2020/8830304 |
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