{"title":"离散裂隙特征对长壁顶板煤稳定性的影响","authors":"LE TienDung, Hong Quang Dao, VU DinhHieu","doi":"10.46544/ams.v27i4.02","DOIUrl":null,"url":null,"abstract":"Discrete fractures may exist in thick coal seam and significantly impact the top coal stability in the Longwall Top Coal Caving method (LTCC) both ahead of shield support (top coal fall) and behind shield support (top coal caving). The top coal stability in such conditions is not well understood in the literature and has been studied from either fall or caving behaviour. In this paper, a discontinuum-based numerical program is used to study longwall top coal stability when discrete fractures exist in coal seam and vary in characteristics (i.e., orientation, density, stiffness, strength, and intersecting fractures). The study demonstrates that the existence of discrete fractures decreases the top coal stability ahead of shield support, particularly in initial face extraction. The parametric study finds that when the fracture orientation makes an angle of 90 degrees to the positive x-axis, it has the least impact on top coal fall. When the fractures plunge into the mined-out area, they facilitate top coal caving and vice versa when they plunge into the unmined area. The study reveals that the fracture density is directly proportional to top coal fall and top coal caving. Meanwhile, the fracture stiffness and strength are inversely proportional to both top coal fall and caving. The study also demonstrates the important role of coal seam characteristics (strength, elastic modulus, and depth) in top coal fall. The findings from this paper can assist engineers in improving panel geometry design and roof control for efficient underground mining when discrete fractures exist and vary in a coal seam.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":null,"pages":null},"PeriodicalIF":2.2000,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Impact of Discrete Fracture Characteristics on Longwall Top Coal Stability\",\"authors\":\"LE TienDung, Hong Quang Dao, VU DinhHieu\",\"doi\":\"10.46544/ams.v27i4.02\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Discrete fractures may exist in thick coal seam and significantly impact the top coal stability in the Longwall Top Coal Caving method (LTCC) both ahead of shield support (top coal fall) and behind shield support (top coal caving). The top coal stability in such conditions is not well understood in the literature and has been studied from either fall or caving behaviour. In this paper, a discontinuum-based numerical program is used to study longwall top coal stability when discrete fractures exist in coal seam and vary in characteristics (i.e., orientation, density, stiffness, strength, and intersecting fractures). The study demonstrates that the existence of discrete fractures decreases the top coal stability ahead of shield support, particularly in initial face extraction. The parametric study finds that when the fracture orientation makes an angle of 90 degrees to the positive x-axis, it has the least impact on top coal fall. When the fractures plunge into the mined-out area, they facilitate top coal caving and vice versa when they plunge into the unmined area. The study reveals that the fracture density is directly proportional to top coal fall and top coal caving. Meanwhile, the fracture stiffness and strength are inversely proportional to both top coal fall and caving. The study also demonstrates the important role of coal seam characteristics (strength, elastic modulus, and depth) in top coal fall. The findings from this paper can assist engineers in improving panel geometry design and roof control for efficient underground mining when discrete fractures exist and vary in a coal seam.\",\"PeriodicalId\":50889,\"journal\":{\"name\":\"Acta Montanistica Slovaca\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2023-02-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Acta Montanistica Slovaca\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.46544/ams.v27i4.02\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Montanistica Slovaca","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.46544/ams.v27i4.02","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
Impact of Discrete Fracture Characteristics on Longwall Top Coal Stability
Discrete fractures may exist in thick coal seam and significantly impact the top coal stability in the Longwall Top Coal Caving method (LTCC) both ahead of shield support (top coal fall) and behind shield support (top coal caving). The top coal stability in such conditions is not well understood in the literature and has been studied from either fall or caving behaviour. In this paper, a discontinuum-based numerical program is used to study longwall top coal stability when discrete fractures exist in coal seam and vary in characteristics (i.e., orientation, density, stiffness, strength, and intersecting fractures). The study demonstrates that the existence of discrete fractures decreases the top coal stability ahead of shield support, particularly in initial face extraction. The parametric study finds that when the fracture orientation makes an angle of 90 degrees to the positive x-axis, it has the least impact on top coal fall. When the fractures plunge into the mined-out area, they facilitate top coal caving and vice versa when they plunge into the unmined area. The study reveals that the fracture density is directly proportional to top coal fall and top coal caving. Meanwhile, the fracture stiffness and strength are inversely proportional to both top coal fall and caving. The study also demonstrates the important role of coal seam characteristics (strength, elastic modulus, and depth) in top coal fall. The findings from this paper can assist engineers in improving panel geometry design and roof control for efficient underground mining when discrete fractures exist and vary in a coal seam.
期刊介绍:
Acta Montanistica Slovaca publishes high quality articles on basic and applied research in the following fields:
geology and geological survey;
mining;
Earth resources;
underground engineering and geotechnics;
mining mechanization, mining transport, deep hole drilling;
ecotechnology and mineralurgy;
process control, automation and applied informatics in raw materials extraction, utilization and processing;
other similar fields.
Acta Montanistica Slovaca is the only scientific journal of this kind in Central, Eastern and South Eastern Europe.
The submitted manuscripts should contribute significantly to the international literature, even if the focus can be regional. Manuscripts should cite the extant and relevant international literature, should clearly state what the wider contribution is (e.g. a novel discovery, application of a new technique or methodology, application of an existing methodology to a new problem), and should discuss the importance of the work in the international context.