Study on coal drawing parameters of deeply buried hard coal seams based on PFC
Abstract The coal seams in the Zhaogu mining area are characterized by great burial depth, hard coal quality, and difficulty in fracturing the top coal. To address the challenges of top-coal drawing in the working face, this study focuses on the external coal pillar working face in the Second Panel....
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Nature Portfolio
2025-07-01
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| Series: | Scientific Reports |
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| Online Access: | https://doi.org/10.1038/s41598-025-08154-4 |
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| author | Li Xinlei Ren Ziyuan Cao Zhengzheng Ren Hao |
| author_facet | Li Xinlei Ren Ziyuan Cao Zhengzheng Ren Hao |
| author_sort | Li Xinlei |
| collection | DOAJ |
| description | Abstract The coal seams in the Zhaogu mining area are characterized by great burial depth, hard coal quality, and difficulty in fracturing the top coal. To address the challenges of top-coal drawing in the working face, this study focuses on the external coal pillar working face in the Second Panel. Through laboratory experiments, field tests, and PFC numerical simulations, the coal drawing parameters and top-coal caving techniques were systematically investigated to provide technical support for on-site production. Key findings include: (1) Borehole observations revealed that adjacent goaf mining activities induced stress redistribution toward deeper zones, promoting full fragmentation of top coal. (2) Numerical simulations demonstrated the significant influence of mining-to-drawing ratio (MDR) on top-coal failure characteristics, with optimal recovery rate (TCRR) achieved at 1:1 MDR. (3) Parameter analysis showed the lowest gangue content occurred at 0.8 m drawing step distance, while single-round multi-opening interval drawing strategy delivered superior economic benefits and higher recovery compared to traditional multi-round approaches. (4) Similarity simulation tests uncovered funnel interaction patterns between adjacent drawing openings, with peak efficiency during initial drawing phases and an overall simulated recovery rate of 86.23%. Field applications confirmed the method’s effectiveness, showing no significant fluctuations in support pressure during operation. The research results provide critical parameter optimization schemes and technical implementation pathways for efficient extraction of deep-buried hard coal seams under complex geological conditions. |
| format | Article |
| id | doaj-art-e2da535227c84efa825d265b5579dce3 |
| institution | DOAJ |
| issn | 2045-2322 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj-art-e2da535227c84efa825d265b5579dce32025-08-20T03:03:37ZengNature PortfolioScientific Reports2045-23222025-07-0115111610.1038/s41598-025-08154-4Study on coal drawing parameters of deeply buried hard coal seams based on PFCLi Xinlei0Ren Ziyuan1Cao Zhengzheng2Ren Hao3Jiaozuo Coal Industry (Group) Xinxiang Energy Co., Ltd.Henan Mine Water Disaster Prevention and Control and Water Resources Utilization Engineering Technology Research Center, Henan Polytechnic UniversityHenan Mine Water Disaster Prevention and Control and Water Resources Utilization Engineering Technology Research Center, Henan Polytechnic UniversityHenan Mine Water Disaster Prevention and Control and Water Resources Utilization Engineering Technology Research Center, Henan Polytechnic UniversityAbstract The coal seams in the Zhaogu mining area are characterized by great burial depth, hard coal quality, and difficulty in fracturing the top coal. To address the challenges of top-coal drawing in the working face, this study focuses on the external coal pillar working face in the Second Panel. Through laboratory experiments, field tests, and PFC numerical simulations, the coal drawing parameters and top-coal caving techniques were systematically investigated to provide technical support for on-site production. Key findings include: (1) Borehole observations revealed that adjacent goaf mining activities induced stress redistribution toward deeper zones, promoting full fragmentation of top coal. (2) Numerical simulations demonstrated the significant influence of mining-to-drawing ratio (MDR) on top-coal failure characteristics, with optimal recovery rate (TCRR) achieved at 1:1 MDR. (3) Parameter analysis showed the lowest gangue content occurred at 0.8 m drawing step distance, while single-round multi-opening interval drawing strategy delivered superior economic benefits and higher recovery compared to traditional multi-round approaches. (4) Similarity simulation tests uncovered funnel interaction patterns between adjacent drawing openings, with peak efficiency during initial drawing phases and an overall simulated recovery rate of 86.23%. Field applications confirmed the method’s effectiveness, showing no significant fluctuations in support pressure during operation. The research results provide critical parameter optimization schemes and technical implementation pathways for efficient extraction of deep-buried hard coal seams under complex geological conditions.https://doi.org/10.1038/s41598-025-08154-4Top coal cavingMining ratioCoal caving step distanceCoal caving methodPFC |
| spellingShingle | Li Xinlei Ren Ziyuan Cao Zhengzheng Ren Hao Study on coal drawing parameters of deeply buried hard coal seams based on PFC Scientific Reports Top coal caving Mining ratio Coal caving step distance Coal caving method PFC |
| title | Study on coal drawing parameters of deeply buried hard coal seams based on PFC |
| title_full | Study on coal drawing parameters of deeply buried hard coal seams based on PFC |
| title_fullStr | Study on coal drawing parameters of deeply buried hard coal seams based on PFC |
| title_full_unstemmed | Study on coal drawing parameters of deeply buried hard coal seams based on PFC |
| title_short | Study on coal drawing parameters of deeply buried hard coal seams based on PFC |
| title_sort | study on coal drawing parameters of deeply buried hard coal seams based on pfc |
| topic | Top coal caving Mining ratio Coal caving step distance Coal caving method PFC |
| url | https://doi.org/10.1038/s41598-025-08154-4 |
| work_keys_str_mv | AT lixinlei studyoncoaldrawingparametersofdeeplyburiedhardcoalseamsbasedonpfc AT renziyuan studyoncoaldrawingparametersofdeeplyburiedhardcoalseamsbasedonpfc AT caozhengzheng studyoncoaldrawingparametersofdeeplyburiedhardcoalseamsbasedonpfc AT renhao studyoncoaldrawingparametersofdeeplyburiedhardcoalseamsbasedonpfc |