Mechanism of Rock Bursts Induced by the Synthetic Action of “Roof Bending and Rock Pillar Prying” in Subvertical Extra-Thick Coal Seams
When studying the rock burst mechanism in subvertical extra-thick coal seams in the Wudong coal mine in Xinjiang, China, most studies focus on rock pillars, while the effect of the roof on rock bursts is usually ignored. In this paper, a rock burst mechanism in subvertical extra-thick coal seams und...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2021-12-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2021.737995/full |
| _version_ | 1818926037036171264 |
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| author | Zhenhua Wu Zhenhua Wu Peng-Zhi Pan Peng-Zhi Pan Jianqiang Chen Xudong Liu Shuting Miao Shuting Miao Peiyang Yu Peiyang Yu |
| author_facet | Zhenhua Wu Zhenhua Wu Peng-Zhi Pan Peng-Zhi Pan Jianqiang Chen Xudong Liu Shuting Miao Shuting Miao Peiyang Yu Peiyang Yu |
| author_sort | Zhenhua Wu |
| collection | DOAJ |
| description | When studying the rock burst mechanism in subvertical extra-thick coal seams in the Wudong coal mine in Xinjiang, China, most studies focus on rock pillars, while the effect of the roof on rock bursts is usually ignored. In this paper, a rock burst mechanism in subvertical extra-thick coal seams under the control of a “roof-rock pillar” is proposed. A theoretical analysis is first performed to explain the effect of roof-rock pillar combinations on rock bursts in coal seams. Numerical modeling and microseismic analysis are implemented to further study the mechanism of rock burst. The main conclusions are as follows: 1) During the mining of the B3+6 coal seam, an obvious microseismic concentration phenomenon is found in both the roof and rock pillar of B3+6. The rock bursts exhibited obvious directionality, and its main failure characteristics are floor heave and sidewall heave, but there will also be some failures such as shoulder socket subsidence in some parts. 2) The stress transfer caused by rock pillar prying is the main reason for the large difference in rock burst occurrence near the vertical and extra thick adjacent coal seams under the same mining depth. 3) Under the same cantilever length, the elastic deformation energy of the roof is much greater than that of the rock pillar, which makes it easier to produce high-energy microseismic events. With an increasing mining depth, the roof will become the dominant factor controlling the occurrence of rock bursts. 4) The high-energy event produced by the rock mass fracture near the coal rock interface easily induces rock bursts, while the high-energy event produced by the fracture at the far end of the rock mass is less likely to induce rock burst. 5) Roof deformation extrusion and rock pillar prying provide high static stress conditions for the occurrence of rock bursts in the B3+6 coal seam. The superposition of the dynamic disturbance caused by roof and rock pillar failure and the high static stress of the coal seam is the main cause of rock burst in the B3+6 coal seam. |
| first_indexed | 2024-12-20T02:50:44Z |
| format | Article |
| id | doaj.art-90f71ec5ef5d485e9ad12ce6b2fa858f |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-12-20T02:50:44Z |
| publishDate | 2021-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-90f71ec5ef5d485e9ad12ce6b2fa858f2022-12-21T19:56:03ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632021-12-01910.3389/feart.2021.737995737995Mechanism of Rock Bursts Induced by the Synthetic Action of “Roof Bending and Rock Pillar Prying” in Subvertical Extra-Thick Coal SeamsZhenhua Wu0Zhenhua Wu1Peng-Zhi Pan2Peng-Zhi Pan3Jianqiang Chen4Xudong Liu5Shuting Miao6Shuting Miao7Peiyang Yu8Peiyang Yu9State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, ChinaUniversity of Chinese Academy of Sciences, Beijing, ChinaState Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, ChinaUniversity of Chinese Academy of Sciences, Beijing, ChinaShenhua Xinjiang Energy Company Limited, Urumqi, ChinaShenhua Xinjiang Energy Company Limited, Urumqi, ChinaState Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, ChinaUniversity of Chinese Academy of Sciences, Beijing, ChinaState Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, ChinaUniversity of Chinese Academy of Sciences, Beijing, ChinaWhen studying the rock burst mechanism in subvertical extra-thick coal seams in the Wudong coal mine in Xinjiang, China, most studies focus on rock pillars, while the effect of the roof on rock bursts is usually ignored. In this paper, a rock burst mechanism in subvertical extra-thick coal seams under the control of a “roof-rock pillar” is proposed. A theoretical analysis is first performed to explain the effect of roof-rock pillar combinations on rock bursts in coal seams. Numerical modeling and microseismic analysis are implemented to further study the mechanism of rock burst. The main conclusions are as follows: 1) During the mining of the B3+6 coal seam, an obvious microseismic concentration phenomenon is found in both the roof and rock pillar of B3+6. The rock bursts exhibited obvious directionality, and its main failure characteristics are floor heave and sidewall heave, but there will also be some failures such as shoulder socket subsidence in some parts. 2) The stress transfer caused by rock pillar prying is the main reason for the large difference in rock burst occurrence near the vertical and extra thick adjacent coal seams under the same mining depth. 3) Under the same cantilever length, the elastic deformation energy of the roof is much greater than that of the rock pillar, which makes it easier to produce high-energy microseismic events. With an increasing mining depth, the roof will become the dominant factor controlling the occurrence of rock bursts. 4) The high-energy event produced by the rock mass fracture near the coal rock interface easily induces rock bursts, while the high-energy event produced by the fracture at the far end of the rock mass is less likely to induce rock burst. 5) Roof deformation extrusion and rock pillar prying provide high static stress conditions for the occurrence of rock bursts in the B3+6 coal seam. The superposition of the dynamic disturbance caused by roof and rock pillar failure and the high static stress of the coal seam is the main cause of rock burst in the B3+6 coal seam.https://www.frontiersin.org/articles/10.3389/feart.2021.737995/fullrock burstssubvertical extra-thick coal seamsadjacent coal seamsroof bendingrock pillar prying |
| spellingShingle | Zhenhua Wu Zhenhua Wu Peng-Zhi Pan Peng-Zhi Pan Jianqiang Chen Xudong Liu Shuting Miao Shuting Miao Peiyang Yu Peiyang Yu Mechanism of Rock Bursts Induced by the Synthetic Action of “Roof Bending and Rock Pillar Prying” in Subvertical Extra-Thick Coal Seams Frontiers in Earth Science rock bursts subvertical extra-thick coal seams adjacent coal seams roof bending rock pillar prying |
| title | Mechanism of Rock Bursts Induced by the Synthetic Action of “Roof Bending and Rock Pillar Prying” in Subvertical Extra-Thick Coal Seams |
| title_full | Mechanism of Rock Bursts Induced by the Synthetic Action of “Roof Bending and Rock Pillar Prying” in Subvertical Extra-Thick Coal Seams |
| title_fullStr | Mechanism of Rock Bursts Induced by the Synthetic Action of “Roof Bending and Rock Pillar Prying” in Subvertical Extra-Thick Coal Seams |
| title_full_unstemmed | Mechanism of Rock Bursts Induced by the Synthetic Action of “Roof Bending and Rock Pillar Prying” in Subvertical Extra-Thick Coal Seams |
| title_short | Mechanism of Rock Bursts Induced by the Synthetic Action of “Roof Bending and Rock Pillar Prying” in Subvertical Extra-Thick Coal Seams |
| title_sort | mechanism of rock bursts induced by the synthetic action of roof bending and rock pillar prying in subvertical extra thick coal seams |
| topic | rock bursts subvertical extra-thick coal seams adjacent coal seams roof bending rock pillar prying |
| url | https://www.frontiersin.org/articles/10.3389/feart.2021.737995/full |
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