Experimental Investigation on Crack Development Characteristics in Shallow Coal Seam Mining in China
The development of cracks in mining is the scientific basis for the safety and environmental exploitation of shallow multiple-seam. According to the “thickness of coal seam, interactive distance, and buried depth,„ four mining coal mines are selected in Shen Fu-Dong Sheng coalfie...
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doaj-02ed863a00514527a9440a437c139f652020-11-24T20:42:10ZengMDPI AGEnergies1996-10732019-04-01127130210.3390/en12071302en12071302Experimental Investigation on Crack Development Characteristics in Shallow Coal Seam Mining in ChinaQingxiang Huang0Yanpeng He1Jian Cao2School of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, ChinaSchool of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, ChinaSchool of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, ChinaThe development of cracks in mining is the scientific basis for the safety and environmental exploitation of shallow multiple-seam. According to the “thickness of coal seam, interactive distance, and buried depth,„ four mining coal mines are selected in Shen Fu-Dong Sheng coalfield (SFDSC). To research the mining conditions of shallow coal seam under different base-load ratio mining conditions and different working faces by the physics simulation and in-sit measurement, the key roof caves are sketched by different colors. This study shows that the typical shallow coal seams in the thin overlying bedrock and thick loose sand layer (LSL) as well as the development of the setup entry cracks (SEC) is dominated by LSL arch damage. The surface cracks are almost directly above the setup entry. The flat seam mining and the SEC development is dominated by parabolic type. The surface cracks are located inside the setup entry. With the mining height increased typically in a shallow coal seam, the rate of crack development and the extent of damaged area increased significantly. The SEC and boundary cracks are fixed. The dynamic periodic cracks (DPC) show the ability of the strata to self-repair. During the multiple-seam mining, the above three kinds of cracks have the phenomenon of activation and development. Through the reasonable coal pillar distance arrangement, the development of boundary cracks can be effectively controlled and the relatively uniform surface settlement and crack closure can be achieved. The purpose of reducing damage mining can also be achieved. Furthermore, it provides scientific support for the green mining in the shallow coal seam.https://www.mdpi.com/1996-1073/12/7/1302shallow coal seammultiple-seam miningcrack growthsketch drawingcoal pillar distancereduce damage mininggreen mining |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Qingxiang Huang Yanpeng He Jian Cao |
spellingShingle |
Qingxiang Huang Yanpeng He Jian Cao Experimental Investigation on Crack Development Characteristics in Shallow Coal Seam Mining in China Energies shallow coal seam multiple-seam mining crack growth sketch drawing coal pillar distance reduce damage mining green mining |
author_facet |
Qingxiang Huang Yanpeng He Jian Cao |
author_sort |
Qingxiang Huang |
title |
Experimental Investigation on Crack Development Characteristics in Shallow Coal Seam Mining in China |
title_short |
Experimental Investigation on Crack Development Characteristics in Shallow Coal Seam Mining in China |
title_full |
Experimental Investigation on Crack Development Characteristics in Shallow Coal Seam Mining in China |
title_fullStr |
Experimental Investigation on Crack Development Characteristics in Shallow Coal Seam Mining in China |
title_full_unstemmed |
Experimental Investigation on Crack Development Characteristics in Shallow Coal Seam Mining in China |
title_sort |
experimental investigation on crack development characteristics in shallow coal seam mining in china |
publisher |
MDPI AG |
series |
Energies |
issn |
1996-1073 |
publishDate |
2019-04-01 |
description |
The development of cracks in mining is the scientific basis for the safety and environmental exploitation of shallow multiple-seam. According to the “thickness of coal seam, interactive distance, and buried depth,„ four mining coal mines are selected in Shen Fu-Dong Sheng coalfield (SFDSC). To research the mining conditions of shallow coal seam under different base-load ratio mining conditions and different working faces by the physics simulation and in-sit measurement, the key roof caves are sketched by different colors. This study shows that the typical shallow coal seams in the thin overlying bedrock and thick loose sand layer (LSL) as well as the development of the setup entry cracks (SEC) is dominated by LSL arch damage. The surface cracks are almost directly above the setup entry. The flat seam mining and the SEC development is dominated by parabolic type. The surface cracks are located inside the setup entry. With the mining height increased typically in a shallow coal seam, the rate of crack development and the extent of damaged area increased significantly. The SEC and boundary cracks are fixed. The dynamic periodic cracks (DPC) show the ability of the strata to self-repair. During the multiple-seam mining, the above three kinds of cracks have the phenomenon of activation and development. Through the reasonable coal pillar distance arrangement, the development of boundary cracks can be effectively controlled and the relatively uniform surface settlement and crack closure can be achieved. The purpose of reducing damage mining can also be achieved. Furthermore, it provides scientific support for the green mining in the shallow coal seam. |
topic |
shallow coal seam multiple-seam mining crack growth sketch drawing coal pillar distance reduce damage mining green mining |
url |
https://www.mdpi.com/1996-1073/12/7/1302 |
work_keys_str_mv |
AT qingxianghuang experimentalinvestigationoncrackdevelopmentcharacteristicsinshallowcoalseammininginchina AT yanpenghe experimentalinvestigationoncrackdevelopmentcharacteristicsinshallowcoalseammininginchina AT jiancao experimentalinvestigationoncrackdevelopmentcharacteristicsinshallowcoalseammininginchina |
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