Research on the coupled support technology of a composite rock beam-retained roadway roof under close coal seams
IntroductionThe technology of gob-side entry retaining without coal pillars in close (distance) coal seams is still immature, and the roof control and support technology in this case is not perfect.MethodsIn this paper, the coupled support technology of a composite rock beam roof under close coal se...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-10-01
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| Series: | Frontiers in Ecology and Evolution |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fevo.2023.1291359/full |
| _version_ | 1797644333536509952 |
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| author | Tingchun Li Tingchun Li Liu Yang Liu Yang Qingwen Zhu Qingwen Zhu Daowei Liu Daowei Liu Yichao Wang Yichao Wang |
| author_facet | Tingchun Li Tingchun Li Liu Yang Liu Yang Qingwen Zhu Qingwen Zhu Daowei Liu Daowei Liu Yichao Wang Yichao Wang |
| author_sort | Tingchun Li |
| collection | DOAJ |
| description | IntroductionThe technology of gob-side entry retaining without coal pillars in close (distance) coal seams is still immature, and the roof control and support technology in this case is not perfect.MethodsIn this paper, the coupled support technology of a composite rock beam roof under close coal seams is systematically studied by using theoretical analysis, numerical simulation and field test.ResultsBoth the floor slip calculation results and numerical simulations indicate that the vertical failure depth in the plastic zone of the #8 coal seam has not penetrated the roof of the #9 coal seam after mining, which is consistent with the field electronic imaging results. A theoretical formula for a composite rock beam model anchored by high-prestressed anchor cables was derived, and a formula for the optimal spacing of anchor cables under noncompressive shear failure of the roof was obtained. Identification of the internal stress hazard region of the rock beam provides a basis for determining the locations of vertical support. Through numerical simulation of different support schemes, including roof cutting, arrangement of high-prestressed anchor cables, and setting up of vertical supports, roof cutting was found to effectively reduce the stress of supporting structure and roof pressure. Setting up of vertical supports can reduce the roof convergence by 25.2%, and coupling with anchor cables can reduce the convergence by more than 49.1%. The feasibility of this support scheme was verified through field tests, with a maximum convergence of 99 mm between the roof and floor.DiscussionThis two-way verification approach, in which the damage degree of the roof of a close coal seam is analyzed through multiple means, targeted support plans are proposed, the support mechanisms are explored, and feedback is conducted through field tests, plays a certain guiding role in solving roof control of the gob-side entry retaining under similar geological conditions. |
| first_indexed | 2024-03-11T14:29:01Z |
| format | Article |
| id | doaj.art-44a8bc7683b341269a7760d6ba294b44 |
| institution | Directory Open Access Journal |
| issn | 2296-701X |
| language | English |
| last_indexed | 2024-03-11T14:29:01Z |
| publishDate | 2023-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Ecology and Evolution |
| spelling | doaj.art-44a8bc7683b341269a7760d6ba294b442023-10-31T11:25:49ZengFrontiers Media S.A.Frontiers in Ecology and Evolution2296-701X2023-10-011110.3389/fevo.2023.12913591291359Research on the coupled support technology of a composite rock beam-retained roadway roof under close coal seamsTingchun Li0Tingchun Li1Liu Yang2Liu Yang3Qingwen Zhu4Qingwen Zhu5Daowei Liu6Daowei Liu7Yichao Wang8Yichao Wang9Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao, ChinaCollege of Civil Engineering and Architecture, Shandong University of Science and Technology, Qingdao, ChinaShandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao, ChinaCollege of Civil Engineering and Architecture, Shandong University of Science and Technology, Qingdao, ChinaShandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao, ChinaCollege of Civil Engineering and Architecture, Shandong University of Science and Technology, Qingdao, ChinaShandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao, ChinaCollege of Civil Engineering and Architecture, Shandong University of Science and Technology, Qingdao, ChinaShandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao, ChinaKey Laboratory of Transportation Tunnel Engineering, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan, ChinaIntroductionThe technology of gob-side entry retaining without coal pillars in close (distance) coal seams is still immature, and the roof control and support technology in this case is not perfect.MethodsIn this paper, the coupled support technology of a composite rock beam roof under close coal seams is systematically studied by using theoretical analysis, numerical simulation and field test.ResultsBoth the floor slip calculation results and numerical simulations indicate that the vertical failure depth in the plastic zone of the #8 coal seam has not penetrated the roof of the #9 coal seam after mining, which is consistent with the field electronic imaging results. A theoretical formula for a composite rock beam model anchored by high-prestressed anchor cables was derived, and a formula for the optimal spacing of anchor cables under noncompressive shear failure of the roof was obtained. Identification of the internal stress hazard region of the rock beam provides a basis for determining the locations of vertical support. Through numerical simulation of different support schemes, including roof cutting, arrangement of high-prestressed anchor cables, and setting up of vertical supports, roof cutting was found to effectively reduce the stress of supporting structure and roof pressure. Setting up of vertical supports can reduce the roof convergence by 25.2%, and coupling with anchor cables can reduce the convergence by more than 49.1%. The feasibility of this support scheme was verified through field tests, with a maximum convergence of 99 mm between the roof and floor.DiscussionThis two-way verification approach, in which the damage degree of the roof of a close coal seam is analyzed through multiple means, targeted support plans are proposed, the support mechanisms are explored, and feedback is conducted through field tests, plays a certain guiding role in solving roof control of the gob-side entry retaining under similar geological conditions.https://www.frontiersin.org/articles/10.3389/fevo.2023.1291359/fullclose coal seam roadwaycharacteristics of roof failuresurrounding rock controlcoupled support designnumerical simulation |
| spellingShingle | Tingchun Li Tingchun Li Liu Yang Liu Yang Qingwen Zhu Qingwen Zhu Daowei Liu Daowei Liu Yichao Wang Yichao Wang Research on the coupled support technology of a composite rock beam-retained roadway roof under close coal seams Frontiers in Ecology and Evolution close coal seam roadway characteristics of roof failure surrounding rock control coupled support design numerical simulation |
| title | Research on the coupled support technology of a composite rock beam-retained roadway roof under close coal seams |
| title_full | Research on the coupled support technology of a composite rock beam-retained roadway roof under close coal seams |
| title_fullStr | Research on the coupled support technology of a composite rock beam-retained roadway roof under close coal seams |
| title_full_unstemmed | Research on the coupled support technology of a composite rock beam-retained roadway roof under close coal seams |
| title_short | Research on the coupled support technology of a composite rock beam-retained roadway roof under close coal seams |
| title_sort | research on the coupled support technology of a composite rock beam retained roadway roof under close coal seams |
| topic | close coal seam roadway characteristics of roof failure surrounding rock control coupled support design numerical simulation |
| url | https://www.frontiersin.org/articles/10.3389/fevo.2023.1291359/full |
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