Experimental Study on Damage and Failure of Coal-Pillar Dams in Coal Mine Underground Reservoir under Dynamic Load
The stability of coal-pillar dams in underground hydraulic engineering works is affected not only by long-term water erosion but also by dynamic loading induced, for example, by roof breaking or fault slipping. In this paper, the water absorption characteristics of coal samples from western China we...
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| Format: | Article |
| Language: | English |
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Wiley
2021-01-01
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| Series: | Geofluids |
| Online Access: | http://dx.doi.org/10.1155/2021/5623650 |
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| author | Qiangling Yao Liqiang Yu Ning Chen Weinan Wang Qiang Xu |
| author_facet | Qiangling Yao Liqiang Yu Ning Chen Weinan Wang Qiang Xu |
| author_sort | Qiangling Yao |
| collection | DOAJ |
| description | The stability of coal-pillar dams in underground hydraulic engineering works is affected not only by long-term water erosion but also by dynamic loading induced, for example, by roof breaking or fault slipping. In this paper, the water absorption characteristics of coal samples from western China were studied by nondestructive immersion tests, and a high-speed camera was used to monitor SHPB tests on samples of varying water content and subjected to various strain rates. Besides, the coal-pillar dam is numerically simulated based on the experimental data and the actual engineering conditions. The results show that, given low strain rate and high water content, the compaction stage accounts for most of the stress-strain curve, whereas the elastic stage accounts for only a relatively small fraction of the stress-strain curve. The dynamic compressive strength and elastic modulus follow exponential and logarithmic functions of strain rate, respectively, exhibiting a significant positive correlation. As the water content increases, the dynamic elastic modulus increases almost linearly, and the compressive strength decreases gradually. Under the same impact load, samples with greater water content fail more rapidly, and the failure is exacerbated by the propagation of parallel cracks to staggered cracks. The average size of coal fragments decreases linearly with increasing strain rate and water content. Simulations indicate that dynamic loading increases the stress concentration on both sides of the dam and expands the high-stress area and plastic zone. The results provide guidance for designing waterproof coal pillars and underground reservoir dams. |
| format | Article |
| id | doaj-art-416b1696c0f246e893a85d7fdbc2c173 |
| institution | Kabale University |
| issn | 1468-8115 1468-8123 |
| language | English |
| publishDate | 2021-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geofluids |
| spelling | doaj-art-416b1696c0f246e893a85d7fdbc2c1732025-02-03T01:27:07ZengWileyGeofluids1468-81151468-81232021-01-01202110.1155/2021/56236505623650Experimental Study on Damage and Failure of Coal-Pillar Dams in Coal Mine Underground Reservoir under Dynamic LoadQiangling Yao0Liqiang Yu1Ning Chen2Weinan Wang3Qiang Xu4State Key Laboratory of Coal Resource and Safe Mining, China University of Mining & Technology, Xuzhou 221116, ChinaState Key Laboratory of Coal Resource and Safe Mining, China University of Mining & Technology, Xuzhou 221116, ChinaState Key Laboratory of Coal Resource and Safe Mining, China University of Mining & Technology, Xuzhou 221116, ChinaState Key Laboratory of Coal Resource and Safe Mining, China University of Mining & Technology, Xuzhou 221116, ChinaState Key Laboratory of Coal Resource and Safe Mining, China University of Mining & Technology, Xuzhou 221116, ChinaThe stability of coal-pillar dams in underground hydraulic engineering works is affected not only by long-term water erosion but also by dynamic loading induced, for example, by roof breaking or fault slipping. In this paper, the water absorption characteristics of coal samples from western China were studied by nondestructive immersion tests, and a high-speed camera was used to monitor SHPB tests on samples of varying water content and subjected to various strain rates. Besides, the coal-pillar dam is numerically simulated based on the experimental data and the actual engineering conditions. The results show that, given low strain rate and high water content, the compaction stage accounts for most of the stress-strain curve, whereas the elastic stage accounts for only a relatively small fraction of the stress-strain curve. The dynamic compressive strength and elastic modulus follow exponential and logarithmic functions of strain rate, respectively, exhibiting a significant positive correlation. As the water content increases, the dynamic elastic modulus increases almost linearly, and the compressive strength decreases gradually. Under the same impact load, samples with greater water content fail more rapidly, and the failure is exacerbated by the propagation of parallel cracks to staggered cracks. The average size of coal fragments decreases linearly with increasing strain rate and water content. Simulations indicate that dynamic loading increases the stress concentration on both sides of the dam and expands the high-stress area and plastic zone. The results provide guidance for designing waterproof coal pillars and underground reservoir dams.http://dx.doi.org/10.1155/2021/5623650 |
| spellingShingle | Qiangling Yao Liqiang Yu Ning Chen Weinan Wang Qiang Xu Experimental Study on Damage and Failure of Coal-Pillar Dams in Coal Mine Underground Reservoir under Dynamic Load Geofluids |
| title | Experimental Study on Damage and Failure of Coal-Pillar Dams in Coal Mine Underground Reservoir under Dynamic Load |
| title_full | Experimental Study on Damage and Failure of Coal-Pillar Dams in Coal Mine Underground Reservoir under Dynamic Load |
| title_fullStr | Experimental Study on Damage and Failure of Coal-Pillar Dams in Coal Mine Underground Reservoir under Dynamic Load |
| title_full_unstemmed | Experimental Study on Damage and Failure of Coal-Pillar Dams in Coal Mine Underground Reservoir under Dynamic Load |
| title_short | Experimental Study on Damage and Failure of Coal-Pillar Dams in Coal Mine Underground Reservoir under Dynamic Load |
| title_sort | experimental study on damage and failure of coal pillar dams in coal mine underground reservoir under dynamic load |
| url | http://dx.doi.org/10.1155/2021/5623650 |
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