Stability evolution mechanisms and control strategies for lower and upper trapezoidal blocks in fully mechanized top-coal caving faces of extra-thick coal seams
In underground coal mining operations, particularly in fully mechanized top-coal caving (FMTC) faces of extra-thick coal seams, structural instability after key stratum fracturing will cause severe deformation and damage to the surrounding rock mass of the working face. The methods of field investig...
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Frontiers Media S.A.
2025-05-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2025.1586733/full |
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| author | Binbin Qin Binbin Qin Binbin Qin Fulian He Qinghua Zhang Qinghua Zhang Zhijun Zhang Zhijun Zhang Zhijun Zhang Guoxi Sun Guoxi Sun Xiaohu Liu |
| author_facet | Binbin Qin Binbin Qin Binbin Qin Fulian He Qinghua Zhang Qinghua Zhang Zhijun Zhang Zhijun Zhang Zhijun Zhang Guoxi Sun Guoxi Sun Xiaohu Liu |
| author_sort | Binbin Qin |
| collection | DOAJ |
| description | In underground coal mining operations, particularly in fully mechanized top-coal caving (FMTC) faces of extra-thick coal seams, structural instability after key stratum fracturing will cause severe deformation and damage to the surrounding rock mass of the working face. The methods of field investigation, theoretical analysis, physical similarity simulation, and engineering tests were employed to investigate the instability characteristics and interaction laws of the lower and upper trapezoidal block structures in the FMTC face in extra-thick coal seams with dual key strata during periods of pressure. A mechanical model of the stability of the lower and upper trapezoidal blocks above the working face with severe and weak periodic pressures was established, and the stability transformation law, interaction relationship, and influencing factors of the stability of the lower and upper trapezoidal blocks with the dual key strata working face in the extra-thick coal seam were studied. The results show that (1) it is easy to induce the sliding instability of the lower and upper trapezoidal blocks with the advance of the working face. (2) The sliding instability coefficients of the lower and upper trapezoidal blocks are positively correlated, whereas the rotational deformation instability coefficients are negatively correlated. (3) An increase in the distance between the lower and upper key strata easily induces sliding instability in the upper trapezoidal block and sliding instability and rotational deformation instability in the lower trapezoidal block. (4) Increasing the mining height could improve the sliding stability of the lower and upper trapezoidal blocks and the rotational deformation stability of the upper trapezoidal block, but it is easy to induce rotational deformation instability of the lower trapezoidal block. (5) A higher support force on hydraulic supports improves sliding stability in lower and upper trapezoidal blocks but does not affect rotational deformation stability. Finally, the rationality and reliability of the study are verified by engineering applications in the 8309 working face of the Tongxin Coal Mine. |
| format | Article |
| id | doaj-art-5456036a3fe54c3badfb3c4c8e1e24fc |
| institution | DOAJ |
| issn | 2296-6463 |
| language | English |
| publishDate | 2025-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj-art-5456036a3fe54c3badfb3c4c8e1e24fc2025-08-20T03:09:44ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632025-05-011310.3389/feart.2025.15867331586733Stability evolution mechanisms and control strategies for lower and upper trapezoidal blocks in fully mechanized top-coal caving faces of extra-thick coal seamsBinbin Qin0Binbin Qin1Binbin Qin2Fulian He3Qinghua Zhang4Qinghua Zhang5Zhijun Zhang6Zhijun Zhang7Zhijun Zhang8Guoxi Sun9Guoxi Sun10Xiaohu Liu11School of Automation Science and Engineering, South China University of Technology, Guangzhou, ChinaPostdoctoral Innovation Practice Base, Guangdong University of Petrochemical Technology, Maoming, ChinaGuangdong Provincial Key Lab of Petrochemical Equipment Fault Diagnosis, Guangdong University of Petrochemical Technology, Maoming, ChinaSchool of Energy and Mining, China University of Mining and Technology, Beijing, ChinaPostdoctoral Innovation Practice Base, Guangdong University of Petrochemical Technology, Maoming, ChinaGuangdong Provincial Key Lab of Petrochemical Equipment Fault Diagnosis, Guangdong University of Petrochemical Technology, Maoming, ChinaSchool of Automation Science and Engineering, South China University of Technology, Guangzhou, ChinaPostdoctoral Innovation Practice Base, Guangdong University of Petrochemical Technology, Maoming, ChinaGuangdong Provincial Key Lab of Petrochemical Equipment Fault Diagnosis, Guangdong University of Petrochemical Technology, Maoming, ChinaPostdoctoral Innovation Practice Base, Guangdong University of Petrochemical Technology, Maoming, ChinaGuangdong Provincial Key Lab of Petrochemical Equipment Fault Diagnosis, Guangdong University of Petrochemical Technology, Maoming, ChinaSchool of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, ChinaIn underground coal mining operations, particularly in fully mechanized top-coal caving (FMTC) faces of extra-thick coal seams, structural instability after key stratum fracturing will cause severe deformation and damage to the surrounding rock mass of the working face. The methods of field investigation, theoretical analysis, physical similarity simulation, and engineering tests were employed to investigate the instability characteristics and interaction laws of the lower and upper trapezoidal block structures in the FMTC face in extra-thick coal seams with dual key strata during periods of pressure. A mechanical model of the stability of the lower and upper trapezoidal blocks above the working face with severe and weak periodic pressures was established, and the stability transformation law, interaction relationship, and influencing factors of the stability of the lower and upper trapezoidal blocks with the dual key strata working face in the extra-thick coal seam were studied. The results show that (1) it is easy to induce the sliding instability of the lower and upper trapezoidal blocks with the advance of the working face. (2) The sliding instability coefficients of the lower and upper trapezoidal blocks are positively correlated, whereas the rotational deformation instability coefficients are negatively correlated. (3) An increase in the distance between the lower and upper key strata easily induces sliding instability in the upper trapezoidal block and sliding instability and rotational deformation instability in the lower trapezoidal block. (4) Increasing the mining height could improve the sliding stability of the lower and upper trapezoidal blocks and the rotational deformation stability of the upper trapezoidal block, but it is easy to induce rotational deformation instability of the lower trapezoidal block. (5) A higher support force on hydraulic supports improves sliding stability in lower and upper trapezoidal blocks but does not affect rotational deformation stability. Finally, the rationality and reliability of the study are verified by engineering applications in the 8309 working face of the Tongxin Coal Mine.https://www.frontiersin.org/articles/10.3389/feart.2025.1586733/fullextra-thick seamperiodic pressurelower and upper trapezoidal blocksstructural instabilitysurrounding rock control |
| spellingShingle | Binbin Qin Binbin Qin Binbin Qin Fulian He Qinghua Zhang Qinghua Zhang Zhijun Zhang Zhijun Zhang Zhijun Zhang Guoxi Sun Guoxi Sun Xiaohu Liu Stability evolution mechanisms and control strategies for lower and upper trapezoidal blocks in fully mechanized top-coal caving faces of extra-thick coal seams Frontiers in Earth Science extra-thick seam periodic pressure lower and upper trapezoidal blocks structural instability surrounding rock control |
| title | Stability evolution mechanisms and control strategies for lower and upper trapezoidal blocks in fully mechanized top-coal caving faces of extra-thick coal seams |
| title_full | Stability evolution mechanisms and control strategies for lower and upper trapezoidal blocks in fully mechanized top-coal caving faces of extra-thick coal seams |
| title_fullStr | Stability evolution mechanisms and control strategies for lower and upper trapezoidal blocks in fully mechanized top-coal caving faces of extra-thick coal seams |
| title_full_unstemmed | Stability evolution mechanisms and control strategies for lower and upper trapezoidal blocks in fully mechanized top-coal caving faces of extra-thick coal seams |
| title_short | Stability evolution mechanisms and control strategies for lower and upper trapezoidal blocks in fully mechanized top-coal caving faces of extra-thick coal seams |
| title_sort | stability evolution mechanisms and control strategies for lower and upper trapezoidal blocks in fully mechanized top coal caving faces of extra thick coal seams |
| topic | extra-thick seam periodic pressure lower and upper trapezoidal blocks structural instability surrounding rock control |
| url | https://www.frontiersin.org/articles/10.3389/feart.2025.1586733/full |
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