Study on the influence of confining pressure and unloading damage on the bursting liability characteristics of coal
The research on the bursting liability of coal under confining pressure and unloading damage is critical in creating prevention mechanisms for coal mass rock bursts in deep underground mines. Cyclic loading and unloading tests of variable stress with a lower limit were performed under multistage con...
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| Format: | Article |
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Frontiers Media S.A.
2023-01-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2023.1104831/full |
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| author | Taotao Du Taotao Du Taotao Du Junfeng Pan Junfeng Pan Junfeng Pan Yongxue Xia Yongxue Xia Yongxue Xia Ruda Sun Ruda Sun Ruda Sun |
| author_facet | Taotao Du Taotao Du Taotao Du Junfeng Pan Junfeng Pan Junfeng Pan Yongxue Xia Yongxue Xia Yongxue Xia Ruda Sun Ruda Sun Ruda Sun |
| author_sort | Taotao Du |
| collection | DOAJ |
| description | The research on the bursting liability of coal under confining pressure and unloading damage is critical in creating prevention mechanisms for coal mass rock bursts in deep underground mines. Cyclic loading and unloading tests of variable stress with a lower limit were performed under multistage confining pressure and different amplitude unloading to explore their influence on the impact tendency of the coal bodies. Meanwhile, the characteristic parameter analysis of acoustic emissions was used to evaluate the failure. The results revealed that the accumulated number and energy of acoustic emission events gradually decreased with increasing the confining pressure. The coal specimen became denser, and the failure mode gradually transitioned from brittle to ductile. With the increase in unloading amplitude, the cumulative number of acoustic emission events in the coal specimens decreases, the damage degree to the coal body increases, the peak load decreases, and the failure mode transitions from ductile to brittle. The increase in confining pressure results in an increase in the input energy and the elastic strain energy, while the increase in the unloading range of the coal body leads to a decrease in the input energy and elastic strain energy. In addition, after the confining pressures of 3 MPa, 6 MPa, and 9 MPa, the residual elastic energy index of the coal specimens increases by 21.76%, 42.92%, and 71.69%, respectively, compared with the room pressure conditions. The residual elastic energy index decreases by 21.11% and 55.38% for the unloading amplitude of 3 MPa and 6 MPa, respectively, compared with the unloaded coal specimen, indicating that the impact tendency of the coal body is enhanced by the confining pressure conditions. |
| first_indexed | 2024-04-10T21:39:04Z |
| format | Article |
| id | doaj.art-438d1d3181064db39d96b06bc63f55eb |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-10T21:39:04Z |
| publishDate | 2023-01-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-438d1d3181064db39d96b06bc63f55eb2023-01-19T06:22:55ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632023-01-011110.3389/feart.2023.11048311104831Study on the influence of confining pressure and unloading damage on the bursting liability characteristics of coalTaotao Du0Taotao Du1Taotao Du2Junfeng Pan3Junfeng Pan4Junfeng Pan5Yongxue Xia6Yongxue Xia7Yongxue Xia8Ruda Sun9Ruda Sun10Ruda Sun11CCTEG Coal Mining Research Institute, Beijing, ChinaChina Coal Research Institute, Beijing, ChinaCoal Mining and Designing Department, Tiandi Science and Technology Co., Ltd., Beijing, ChinaCCTEG Coal Mining Research Institute, Beijing, ChinaChina Coal Research Institute, Beijing, ChinaCoal Mining and Designing Department, Tiandi Science and Technology Co., Ltd., Beijing, ChinaCCTEG Coal Mining Research Institute, Beijing, ChinaChina Coal Research Institute, Beijing, ChinaCoal Mining and Designing Department, Tiandi Science and Technology Co., Ltd., Beijing, ChinaCCTEG Coal Mining Research Institute, Beijing, ChinaChina Coal Research Institute, Beijing, ChinaCoal Mining and Designing Department, Tiandi Science and Technology Co., Ltd., Beijing, ChinaThe research on the bursting liability of coal under confining pressure and unloading damage is critical in creating prevention mechanisms for coal mass rock bursts in deep underground mines. Cyclic loading and unloading tests of variable stress with a lower limit were performed under multistage confining pressure and different amplitude unloading to explore their influence on the impact tendency of the coal bodies. Meanwhile, the characteristic parameter analysis of acoustic emissions was used to evaluate the failure. The results revealed that the accumulated number and energy of acoustic emission events gradually decreased with increasing the confining pressure. The coal specimen became denser, and the failure mode gradually transitioned from brittle to ductile. With the increase in unloading amplitude, the cumulative number of acoustic emission events in the coal specimens decreases, the damage degree to the coal body increases, the peak load decreases, and the failure mode transitions from ductile to brittle. The increase in confining pressure results in an increase in the input energy and the elastic strain energy, while the increase in the unloading range of the coal body leads to a decrease in the input energy and elastic strain energy. In addition, after the confining pressures of 3 MPa, 6 MPa, and 9 MPa, the residual elastic energy index of the coal specimens increases by 21.76%, 42.92%, and 71.69%, respectively, compared with the room pressure conditions. The residual elastic energy index decreases by 21.11% and 55.38% for the unloading amplitude of 3 MPa and 6 MPa, respectively, compared with the unloaded coal specimen, indicating that the impact tendency of the coal body is enhanced by the confining pressure conditions.https://www.frontiersin.org/articles/10.3389/feart.2023.1104831/fullcoalbursting liabilityconfining pressureunloading effectresidual elastic energy index |
| spellingShingle | Taotao Du Taotao Du Taotao Du Junfeng Pan Junfeng Pan Junfeng Pan Yongxue Xia Yongxue Xia Yongxue Xia Ruda Sun Ruda Sun Ruda Sun Study on the influence of confining pressure and unloading damage on the bursting liability characteristics of coal Frontiers in Earth Science coal bursting liability confining pressure unloading effect residual elastic energy index |
| title | Study on the influence of confining pressure and unloading damage on the bursting liability characteristics of coal |
| title_full | Study on the influence of confining pressure and unloading damage on the bursting liability characteristics of coal |
| title_fullStr | Study on the influence of confining pressure and unloading damage on the bursting liability characteristics of coal |
| title_full_unstemmed | Study on the influence of confining pressure and unloading damage on the bursting liability characteristics of coal |
| title_short | Study on the influence of confining pressure and unloading damage on the bursting liability characteristics of coal |
| title_sort | study on the influence of confining pressure and unloading damage on the bursting liability characteristics of coal |
| topic | coal bursting liability confining pressure unloading effect residual elastic energy index |
| url | https://www.frontiersin.org/articles/10.3389/feart.2023.1104831/full |
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