Investigation of the anisotropic mechanical response of layered shales
Abstract Layered shales exist widely and are often encountered during shale gas development. However, the mechanical response of layered shales is significantly affected by the existence of beddings, resulting in the obvious anisotropy characteristics regarding deformation, strength and failure mode...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2023-12-01
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| Series: | Energy Science & Engineering |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ese3.1611 |
| _version_ | 1797391392484360192 |
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| author | Min Gao Bin Gong Zhengzhao Liang Shanpo Jia Jiuqun Zou |
| author_facet | Min Gao Bin Gong Zhengzhao Liang Shanpo Jia Jiuqun Zou |
| author_sort | Min Gao |
| collection | DOAJ |
| description | Abstract Layered shales exist widely and are often encountered during shale gas development. However, the mechanical response of layered shales is significantly affected by the existence of beddings, resulting in the obvious anisotropy characteristics regarding deformation, strength and failure mode. To clarify the underlying mechanisms of shale anisotropy that control the safety of engineering projects, the numerical simulation and theoretical analysis were conducted. The results show that with the growth of confining pressure, the compressive resistance of shales gradually increases, the shear fractures govern the instability and the anisotropy index decreases. Furthermore, several strength criteria for layered rock masses were summarized, and the modified Jaeger strength criterion was proposed by introducing the anisotropic parameter Rcθ. It can effectively reflect the failure modes and strength features of layered shales under triaxial conditions with a higher accuracy. Besides, the variation of cohesion and internal friction angle of layered shale samples was comprehensively analysed under the triaxial conditions. Clearly, as the inclination angle of bedding planes increases, the cohesion of layered shales first decreases, but then increases under triaxial compression, showing the ‘U’‐shaped changing trend. Additionally, the internal friction angle of layered shales gradually increases with the increase in the inclination of bedding planes. |
| first_indexed | 2024-03-08T23:32:17Z |
| format | Article |
| id | doaj.art-00542192571f45879fb4a801d08c5272 |
| institution | Directory Open Access Journal |
| issn | 2050-0505 |
| language | English |
| last_indexed | 2024-03-08T23:32:17Z |
| publishDate | 2023-12-01 |
| publisher | Wiley |
| record_format | Article |
| series | Energy Science & Engineering |
| spelling | doaj.art-00542192571f45879fb4a801d08c52722023-12-14T10:54:26ZengWileyEnergy Science & Engineering2050-05052023-12-0111124737475410.1002/ese3.1611Investigation of the anisotropic mechanical response of layered shalesMin Gao0Bin Gong1Zhengzhao Liang2Shanpo Jia3Jiuqun Zou4Engineering Research Center of Underground Mine Construction (Chinese Ministry of Education) Anhui University of Science and Technology Huainan ChinaDepartment of Civil and Environmental Engineering Brunel University London London UKState Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian ChinaSchool of Earth Science Northeast Petroleum University Daqing ChinaEngineering Research Center of Underground Mine Construction (Chinese Ministry of Education) Anhui University of Science and Technology Huainan ChinaAbstract Layered shales exist widely and are often encountered during shale gas development. However, the mechanical response of layered shales is significantly affected by the existence of beddings, resulting in the obvious anisotropy characteristics regarding deformation, strength and failure mode. To clarify the underlying mechanisms of shale anisotropy that control the safety of engineering projects, the numerical simulation and theoretical analysis were conducted. The results show that with the growth of confining pressure, the compressive resistance of shales gradually increases, the shear fractures govern the instability and the anisotropy index decreases. Furthermore, several strength criteria for layered rock masses were summarized, and the modified Jaeger strength criterion was proposed by introducing the anisotropic parameter Rcθ. It can effectively reflect the failure modes and strength features of layered shales under triaxial conditions with a higher accuracy. Besides, the variation of cohesion and internal friction angle of layered shale samples was comprehensively analysed under the triaxial conditions. Clearly, as the inclination angle of bedding planes increases, the cohesion of layered shales first decreases, but then increases under triaxial compression, showing the ‘U’‐shaped changing trend. Additionally, the internal friction angle of layered shales gradually increases with the increase in the inclination of bedding planes.https://doi.org/10.1002/ese3.1611anisotropyfailure criterionlayered shalesshale gas developmenttriaxial compression |
| spellingShingle | Min Gao Bin Gong Zhengzhao Liang Shanpo Jia Jiuqun Zou Investigation of the anisotropic mechanical response of layered shales Energy Science & Engineering anisotropy failure criterion layered shales shale gas development triaxial compression |
| title | Investigation of the anisotropic mechanical response of layered shales |
| title_full | Investigation of the anisotropic mechanical response of layered shales |
| title_fullStr | Investigation of the anisotropic mechanical response of layered shales |
| title_full_unstemmed | Investigation of the anisotropic mechanical response of layered shales |
| title_short | Investigation of the anisotropic mechanical response of layered shales |
| title_sort | investigation of the anisotropic mechanical response of layered shales |
| topic | anisotropy failure criterion layered shales shale gas development triaxial compression |
| url | https://doi.org/10.1002/ese3.1611 |
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