Experimental study on the effect of loading rate on the strain energy accumulation and release during the weakening process of circular-tunnel
Abstract The weakening of circular tunnels is a global problem that has not been resolved satisfactorily. In the tunnelling process, surrounding rock of circular-tunnel performs a process of “excavating → weakening → continuous excavating → weakening strengthens”. Different rates of excavation affec...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Springer
2024-04-01
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| Series: | Geomechanics and Geophysics for Geo-Energy and Geo-Resources |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/s40948-024-00785-7 |
| _version_ | 1797209012190576640 |
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| author | Xun You Yunmin Wang Xiangxin Liu Kui Zhao Zhengnan Zhang |
| author_facet | Xun You Yunmin Wang Xiangxin Liu Kui Zhao Zhengnan Zhang |
| author_sort | Xun You |
| collection | DOAJ |
| description | Abstract The weakening of circular tunnels is a global problem that has not been resolved satisfactorily. In the tunnelling process, surrounding rock of circular-tunnel performs a process of “excavating → weakening → continuous excavating → weakening strengthens”. Different rates of excavation affect the stress adjustment of the surrounding rock, and also have an impact on the weakening of a circular-tunnel. An instability failure test was conducted on a circular-tunnel with varying vertical loading rates. The loading rate was utilized as a representative measure for the excavation rate on the site. The results showed that the weakening process of a circular-tunnel can be divided into four distinct phases, hydrostatic pressure (E1), particle ejection (E2), flake stripping (E3), and instability (E4). The ordering of these phases is E3 > E4 > E1 > E2. In the weakening process of a circular-tunnel, the root cause is the original stress level, while the essential factor is the engineering disturbance. A faster vertical loading rate leads to greater stress adjustment, higher strain energy accumulation, and an increased probability of circular-tunnel instability. The presence of a quiet period of AE events in the middle and later phases of flake stripping is a precursory characteristic of circular-tunnel instability. This study has both theoretical and practical significance in terms of revealing the mechanism of circular-tunnel instability and achieving a reasonable arrangement of the circular-tunnel support process. |
| first_indexed | 2024-04-24T09:47:56Z |
| format | Article |
| id | doaj.art-9dd02fce78644e3eac005d1e848d8e18 |
| institution | Directory Open Access Journal |
| issn | 2363-8419 2363-8427 |
| language | English |
| last_indexed | 2024-04-24T09:47:56Z |
| publishDate | 2024-04-01 |
| publisher | Springer |
| record_format | Article |
| series | Geomechanics and Geophysics for Geo-Energy and Geo-Resources |
| spelling | doaj.art-9dd02fce78644e3eac005d1e848d8e182024-04-14T11:32:30ZengSpringerGeomechanics and Geophysics for Geo-Energy and Geo-Resources2363-84192363-84272024-04-0110111510.1007/s40948-024-00785-7Experimental study on the effect of loading rate on the strain energy accumulation and release during the weakening process of circular-tunnelXun You0Yunmin Wang1Xiangxin Liu2Kui Zhao3Zhengnan Zhang4School of Resource and Environmental EngineeringSchool of Resource and Environmental EngineeringSchool of Civil and Surveying and Mapping Engineering, Jiangxi University of Science and TechnologySchool of Resource and Environmental EngineeringSchool of Resource and Environmental EngineeringAbstract The weakening of circular tunnels is a global problem that has not been resolved satisfactorily. In the tunnelling process, surrounding rock of circular-tunnel performs a process of “excavating → weakening → continuous excavating → weakening strengthens”. Different rates of excavation affect the stress adjustment of the surrounding rock, and also have an impact on the weakening of a circular-tunnel. An instability failure test was conducted on a circular-tunnel with varying vertical loading rates. The loading rate was utilized as a representative measure for the excavation rate on the site. The results showed that the weakening process of a circular-tunnel can be divided into four distinct phases, hydrostatic pressure (E1), particle ejection (E2), flake stripping (E3), and instability (E4). The ordering of these phases is E3 > E4 > E1 > E2. In the weakening process of a circular-tunnel, the root cause is the original stress level, while the essential factor is the engineering disturbance. A faster vertical loading rate leads to greater stress adjustment, higher strain energy accumulation, and an increased probability of circular-tunnel instability. The presence of a quiet period of AE events in the middle and later phases of flake stripping is a precursory characteristic of circular-tunnel instability. This study has both theoretical and practical significance in terms of revealing the mechanism of circular-tunnel instability and achieving a reasonable arrangement of the circular-tunnel support process.https://doi.org/10.1007/s40948-024-00785-7Loading rateCircular-tunnelWeakening processStrain energy accumulationStrain energy release |
| spellingShingle | Xun You Yunmin Wang Xiangxin Liu Kui Zhao Zhengnan Zhang Experimental study on the effect of loading rate on the strain energy accumulation and release during the weakening process of circular-tunnel Geomechanics and Geophysics for Geo-Energy and Geo-Resources Loading rate Circular-tunnel Weakening process Strain energy accumulation Strain energy release |
| title | Experimental study on the effect of loading rate on the strain energy accumulation and release during the weakening process of circular-tunnel |
| title_full | Experimental study on the effect of loading rate on the strain energy accumulation and release during the weakening process of circular-tunnel |
| title_fullStr | Experimental study on the effect of loading rate on the strain energy accumulation and release during the weakening process of circular-tunnel |
| title_full_unstemmed | Experimental study on the effect of loading rate on the strain energy accumulation and release during the weakening process of circular-tunnel |
| title_short | Experimental study on the effect of loading rate on the strain energy accumulation and release during the weakening process of circular-tunnel |
| title_sort | experimental study on the effect of loading rate on the strain energy accumulation and release during the weakening process of circular tunnel |
| topic | Loading rate Circular-tunnel Weakening process Strain energy accumulation Strain energy release |
| url | https://doi.org/10.1007/s40948-024-00785-7 |
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