Failure and development height of overlying rock of a water flowing fracture in goaf under a karst aquifer

Abstract The factors leading to mine water inrush accidents are mainly sources of water, water channels, and intensity of water inrush. Mine water rush depends mostly on whether damage leads to the overlying strata of the working face penetrating the overlying aquifer. There is therefore a need to c...

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Main Authors: Lulin Zheng, Xiong Liu, Qing Qiu, Youwen Tian, Weide Ren, Jin Xu, Xiaokun Wang
Format: Article
Language:English
Published: Nature Portfolio 2025-01-01
Series:Scientific Reports
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Online Access:https://doi.org/10.1038/s41598-025-86676-7
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author Lulin Zheng
Xiong Liu
Qing Qiu
Youwen Tian
Weide Ren
Jin Xu
Xiaokun Wang
author_facet Lulin Zheng
Xiong Liu
Qing Qiu
Youwen Tian
Weide Ren
Jin Xu
Xiaokun Wang
author_sort Lulin Zheng
collection DOAJ
description Abstract The factors leading to mine water inrush accidents are mainly sources of water, water channels, and intensity of water inrush. Mine water rush depends mostly on whether damage leads to the overlying strata of the working face penetrating the overlying aquifer. There is therefore a need to characterize how the overlying strata of the coal seam roof fails and the development height of the water-conducting fracture zone during a roof water inrush incident. This study focuses on the Longfeng Coal Mine, northern Guizhou coalfield. Samples of rock from the roof coal seam were obtained by drilling and coring and examined under a scanning electron microscope. The results showed an undeveloped state of primary cracks in the overlying strata of the coal seam roof, with the water channel occurring mainly along mining-induced cracks. Four key strata were identified, and their fracture steps were calculated through integrating the results of the physical test of the overlying rock of the coal seam. The key strata break when the advancing distance of the working face exceeds their fracture steps. At this point, water-conducting cracks develop upwards. Simulation by FLAC3D allowed the analysis of vertical displacement, vertical stress, and evolution of the plastic zone of the roof overburden rock under different working face advancing distances. The results show that the changes in vertical stress and displacement in overburden rock initially increased rapidly, with this rate of increase subsequently slowing. The shape and maximum height of the plastic failure zone was typical trapezoid and 46.12 m, respectively. Finally, the height of the water-conducting fracture zone determined on site was 42–51.8 m. The good agreement between numerical simulation and measurements confirms that the results of this study can guide practical engineering.
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spelling doaj-art-c6d637cc4f5a4b119d72dbf86709777b2025-01-26T12:32:15ZengNature PortfolioScientific Reports2045-23222025-01-0115111910.1038/s41598-025-86676-7Failure and development height of overlying rock of a water flowing fracture in goaf under a karst aquiferLulin Zheng0Xiong Liu1Qing Qiu2Youwen Tian3Weide Ren4Jin Xu5Xiaokun Wang6Mining College, Guizhou UniversityMining College, Guizhou UniversityMining College, Guizhou UniversityGuizhou Lindong Coal Industry Development Co., Ltd. Longfeng Coal MineGuizhou Lindong Coal Industry Development Co., Ltd. Longfeng Coal MineMining College, Guizhou UniversityMining College, Guizhou UniversityAbstract The factors leading to mine water inrush accidents are mainly sources of water, water channels, and intensity of water inrush. Mine water rush depends mostly on whether damage leads to the overlying strata of the working face penetrating the overlying aquifer. There is therefore a need to characterize how the overlying strata of the coal seam roof fails and the development height of the water-conducting fracture zone during a roof water inrush incident. This study focuses on the Longfeng Coal Mine, northern Guizhou coalfield. Samples of rock from the roof coal seam were obtained by drilling and coring and examined under a scanning electron microscope. The results showed an undeveloped state of primary cracks in the overlying strata of the coal seam roof, with the water channel occurring mainly along mining-induced cracks. Four key strata were identified, and their fracture steps were calculated through integrating the results of the physical test of the overlying rock of the coal seam. The key strata break when the advancing distance of the working face exceeds their fracture steps. At this point, water-conducting cracks develop upwards. Simulation by FLAC3D allowed the analysis of vertical displacement, vertical stress, and evolution of the plastic zone of the roof overburden rock under different working face advancing distances. The results show that the changes in vertical stress and displacement in overburden rock initially increased rapidly, with this rate of increase subsequently slowing. The shape and maximum height of the plastic failure zone was typical trapezoid and 46.12 m, respectively. Finally, the height of the water-conducting fracture zone determined on site was 42–51.8 m. The good agreement between numerical simulation and measurements confirms that the results of this study can guide practical engineering.https://doi.org/10.1038/s41598-025-86676-7Mine water inrushRule of overlying strata damageHeight of fractured water-conducting zoneKey stratumFLAC3D
spellingShingle Lulin Zheng
Xiong Liu
Qing Qiu
Youwen Tian
Weide Ren
Jin Xu
Xiaokun Wang
Failure and development height of overlying rock of a water flowing fracture in goaf under a karst aquifer
Scientific Reports
Mine water inrush
Rule of overlying strata damage
Height of fractured water-conducting zone
Key stratum
FLAC3D
title Failure and development height of overlying rock of a water flowing fracture in goaf under a karst aquifer
title_full Failure and development height of overlying rock of a water flowing fracture in goaf under a karst aquifer
title_fullStr Failure and development height of overlying rock of a water flowing fracture in goaf under a karst aquifer
title_full_unstemmed Failure and development height of overlying rock of a water flowing fracture in goaf under a karst aquifer
title_short Failure and development height of overlying rock of a water flowing fracture in goaf under a karst aquifer
title_sort failure and development height of overlying rock of a water flowing fracture in goaf under a karst aquifer
topic Mine water inrush
Rule of overlying strata damage
Height of fractured water-conducting zone
Key stratum
FLAC3D
url https://doi.org/10.1038/s41598-025-86676-7
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