Effects of inclination angle and unloading rate of confining pressure on triaxial unloading-induced slip behaviors of shale fractures
The effects of inclination angle θ and unloading rate of confining pressure Uc on the unloading-induced slip behaviors of shale fractures were investigated by conducting triaxial unloading-induced fracture slip experiments. The variations in mechanical stability, frictional behavior, and morphology...
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Frontiers Media S.A.
2025-02-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2025.1499268/full |
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| author | Zhe Yuan Zhe Yuan Yongna Cao Tao Zhang Tao Zhang Shuchen Li Xianda Feng |
| author_facet | Zhe Yuan Zhe Yuan Yongna Cao Tao Zhang Tao Zhang Shuchen Li Xianda Feng |
| author_sort | Zhe Yuan |
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| description | The effects of inclination angle θ and unloading rate of confining pressure Uc on the unloading-induced slip behaviors of shale fractures were investigated by conducting triaxial unloading-induced fracture slip experiments. The variations in mechanical stability, frictional behavior, and morphology variation of shale fractures were systematically explored. The results show that with the continuous unloading of confining pressure, the fractures were initiated to slip, then entered the quasi-static slip stage, and eventually entered the dynamic slip stage in sequence. The occurrence of stick-slip events in the quasi-static slip stage was strongly influenced by the θ and Uc. As θ increases from 30° to 50°, the stick-slip events occurred from 0 to 3 times and from 1 to 3 times for Uc = 0.1 MPa/min and 1 MPa/min, respectively. The θ and Uc have a great influence on the interaction mode of the fractures, which directly affects the frictional behavior of the fractures. The slipping failure behavior of the fracture surfaces is mainly controlled by θ, while Uc plays different roles for the samples with different θ. With the increase in θ, the interaction form between asperities during the slip process may be changed into non-tight contact stage. The increase in θ may enhance or weanken the anisotropy of JRC, depending on whether the Uc reached a certain rate between 0.1 MPa/min and 1 MPa/min. Our results may shed light on the seismicity mitigation and safe exploitation of shale gas. |
| format | Article |
| id | doaj-art-79562cc3445648238038241448e7125d |
| institution | Kabale University |
| issn | 2296-6463 |
| language | English |
| publishDate | 2025-02-01 |
| publisher | Frontiers Media S.A. |
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| series | Frontiers in Earth Science |
| spelling | doaj-art-79562cc3445648238038241448e7125d2025-02-05T07:32:58ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632025-02-011310.3389/feart.2025.14992681499268Effects of inclination angle and unloading rate of confining pressure on triaxial unloading-induced slip behaviors of shale fracturesZhe Yuan0Zhe Yuan1Yongna Cao2Tao Zhang3Tao Zhang4Shuchen Li5Xianda Feng6Highway School, Chang’an University, Xi’an, ChinaJinan Traffic Engineering Quality and Safety Center, Jinan, ChinaJinan Traffic Engineering Quality and Safety Center, Jinan, ChinaJinan Traffic Engineering Quality and Safety Center, Jinan, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou, ChinaSchool of Future Technology, Shandong University, Jinan, ChinaSchool of Civil Engineering and Architecture, University of Jinan, Jinan, ChinaThe effects of inclination angle θ and unloading rate of confining pressure Uc on the unloading-induced slip behaviors of shale fractures were investigated by conducting triaxial unloading-induced fracture slip experiments. The variations in mechanical stability, frictional behavior, and morphology variation of shale fractures were systematically explored. The results show that with the continuous unloading of confining pressure, the fractures were initiated to slip, then entered the quasi-static slip stage, and eventually entered the dynamic slip stage in sequence. The occurrence of stick-slip events in the quasi-static slip stage was strongly influenced by the θ and Uc. As θ increases from 30° to 50°, the stick-slip events occurred from 0 to 3 times and from 1 to 3 times for Uc = 0.1 MPa/min and 1 MPa/min, respectively. The θ and Uc have a great influence on the interaction mode of the fractures, which directly affects the frictional behavior of the fractures. The slipping failure behavior of the fracture surfaces is mainly controlled by θ, while Uc plays different roles for the samples with different θ. With the increase in θ, the interaction form between asperities during the slip process may be changed into non-tight contact stage. The increase in θ may enhance or weanken the anisotropy of JRC, depending on whether the Uc reached a certain rate between 0.1 MPa/min and 1 MPa/min. Our results may shed light on the seismicity mitigation and safe exploitation of shale gas.https://www.frontiersin.org/articles/10.3389/feart.2025.1499268/fullinclination angleunloading rate of confining pressuretriaxial unloading-induced slipslip behaviorshale fracture |
| spellingShingle | Zhe Yuan Zhe Yuan Yongna Cao Tao Zhang Tao Zhang Shuchen Li Xianda Feng Effects of inclination angle and unloading rate of confining pressure on triaxial unloading-induced slip behaviors of shale fractures Frontiers in Earth Science inclination angle unloading rate of confining pressure triaxial unloading-induced slip slip behavior shale fracture |
| title | Effects of inclination angle and unloading rate of confining pressure on triaxial unloading-induced slip behaviors of shale fractures |
| title_full | Effects of inclination angle and unloading rate of confining pressure on triaxial unloading-induced slip behaviors of shale fractures |
| title_fullStr | Effects of inclination angle and unloading rate of confining pressure on triaxial unloading-induced slip behaviors of shale fractures |
| title_full_unstemmed | Effects of inclination angle and unloading rate of confining pressure on triaxial unloading-induced slip behaviors of shale fractures |
| title_short | Effects of inclination angle and unloading rate of confining pressure on triaxial unloading-induced slip behaviors of shale fractures |
| title_sort | effects of inclination angle and unloading rate of confining pressure on triaxial unloading induced slip behaviors of shale fractures |
| topic | inclination angle unloading rate of confining pressure triaxial unloading-induced slip slip behavior shale fracture |
| url | https://www.frontiersin.org/articles/10.3389/feart.2025.1499268/full |
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