Study on “Triaxial Loading-Unloading-Uniaxial Loading” and Microscopic Damage Test of Sandstone
To study the weakening process, deformation, and failure characteristics of rock masses surrounding deep chambers under complex stress environments, triaxial loading tests along with triaxial loading/unloading followed by uniaxial loading tests were conducted on sandstone specimens. The internal mic...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2020-03-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/article/10.3389/feart.2020.00078/full |
| _version_ | 1828393812050837504 |
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| author | Chao Yuan Chao Yuan Chao Yuan Yuning Guo Wenjun Wang Wenjun Wang Wenjun Wang Liming Cao Lei Fan Cong Huang |
| author_facet | Chao Yuan Chao Yuan Chao Yuan Yuning Guo Wenjun Wang Wenjun Wang Wenjun Wang Liming Cao Lei Fan Cong Huang |
| author_sort | Chao Yuan |
| collection | DOAJ |
| description | To study the weakening process, deformation, and failure characteristics of rock masses surrounding deep chambers under complex stress environments, triaxial loading tests along with triaxial loading/unloading followed by uniaxial loading tests were conducted on sandstone specimens. The internal microcracks of the specimens under the loading and unloading of triaxial confining pressure were observed by scanning electron microscopy. The results revealed the inherent mechanism of plastic deformation (irreversible deformation) of the rock mass under different confining pressures. Under uniaxial loading and triaxial loading, the sandstone specimens exhibited X-shaped shear failure and single shear failure, respectively. In contrast, the sandstone samples subjected to the loading and unloading of triaxial confining pressure followed by uniaxial loading showed multiple shear fracture surfaces and fine fissures along the axial direction. A larger initial axial pressure of the sandstone specimen corresponded to a smaller uniaxial loading strength after unloading the confining pressure, a greater amount of plastic deformation, more macro- and microfissures, and more severe damage to the specimen. These results show that the final failure mode, strength, degree of damage, and plastic deformation of sandstone specimens are related to the stress state at the time of failure along with the loading history before failure. |
| first_indexed | 2024-12-10T07:44:59Z |
| format | Article |
| id | doaj.art-b090883423794a3cb265ec7c9232b27c |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-12-10T07:44:59Z |
| publishDate | 2020-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-b090883423794a3cb265ec7c9232b27c2022-12-22T01:57:13ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632020-03-01810.3389/feart.2020.00078525666Study on “Triaxial Loading-Unloading-Uniaxial Loading” and Microscopic Damage Test of SandstoneChao Yuan0Chao Yuan1Chao Yuan2Yuning Guo3Wenjun Wang4Wenjun Wang5Wenjun Wang6Liming Cao7Lei Fan8Cong Huang9Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines, Xiangtan, ChinaHunan Key Laboratory of Safe Mining Techniques of Coal Mines, Xiangtan, ChinaSchool of Resources, Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan, ChinaSchool of Resources, Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan, ChinaWork Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines, Xiangtan, ChinaHunan Key Laboratory of Safe Mining Techniques of Coal Mines, Xiangtan, ChinaSchool of Resources, Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan, ChinaSchool of Resources, Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan, ChinaSchool of Resources, Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan, ChinaSchool of Resources, Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan, ChinaTo study the weakening process, deformation, and failure characteristics of rock masses surrounding deep chambers under complex stress environments, triaxial loading tests along with triaxial loading/unloading followed by uniaxial loading tests were conducted on sandstone specimens. The internal microcracks of the specimens under the loading and unloading of triaxial confining pressure were observed by scanning electron microscopy. The results revealed the inherent mechanism of plastic deformation (irreversible deformation) of the rock mass under different confining pressures. Under uniaxial loading and triaxial loading, the sandstone specimens exhibited X-shaped shear failure and single shear failure, respectively. In contrast, the sandstone samples subjected to the loading and unloading of triaxial confining pressure followed by uniaxial loading showed multiple shear fracture surfaces and fine fissures along the axial direction. A larger initial axial pressure of the sandstone specimen corresponded to a smaller uniaxial loading strength after unloading the confining pressure, a greater amount of plastic deformation, more macro- and microfissures, and more severe damage to the specimen. These results show that the final failure mode, strength, degree of damage, and plastic deformation of sandstone specimens are related to the stress state at the time of failure along with the loading history before failure.https://www.frontiersin.org/article/10.3389/feart.2020.00078/fullstrengthplastic deformationfailure patternmacrofissuremicrofissure |
| spellingShingle | Chao Yuan Chao Yuan Chao Yuan Yuning Guo Wenjun Wang Wenjun Wang Wenjun Wang Liming Cao Lei Fan Cong Huang Study on “Triaxial Loading-Unloading-Uniaxial Loading” and Microscopic Damage Test of Sandstone Frontiers in Earth Science strength plastic deformation failure pattern macrofissure microfissure |
| title | Study on “Triaxial Loading-Unloading-Uniaxial Loading” and Microscopic Damage Test of Sandstone |
| title_full | Study on “Triaxial Loading-Unloading-Uniaxial Loading” and Microscopic Damage Test of Sandstone |
| title_fullStr | Study on “Triaxial Loading-Unloading-Uniaxial Loading” and Microscopic Damage Test of Sandstone |
| title_full_unstemmed | Study on “Triaxial Loading-Unloading-Uniaxial Loading” and Microscopic Damage Test of Sandstone |
| title_short | Study on “Triaxial Loading-Unloading-Uniaxial Loading” and Microscopic Damage Test of Sandstone |
| title_sort | study on triaxial loading unloading uniaxial loading and microscopic damage test of sandstone |
| topic | strength plastic deformation failure pattern macrofissure microfissure |
| url | https://www.frontiersin.org/article/10.3389/feart.2020.00078/full |
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