Anisotropy and energy evolution mechanism of rock mass under true triaxial loading-unloading
In the process of underground excavation, the surrounding rock is in a very complex stress environment, especially under the influence of its anisotropy, the occurrence of dynamic disaster is hidden. In this paper, the loading and unloading tests of sandstone in different principal stress directions...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | zho |
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Editorial Office of Journal of China Coal Society
2023-04-01
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| Series: | Meitan xuebao |
| Subjects: | |
| Online Access: | http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2022.0766 |
| _version_ | 1797793844785315840 |
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| author | Wensong XU Guangming ZHAO Xiangrui MENG Zhixi LIU Chongyan LIU Minjie QI |
| author_facet | Wensong XU Guangming ZHAO Xiangrui MENG Zhixi LIU Chongyan LIU Minjie QI |
| author_sort | Wensong XU |
| collection | DOAJ |
| description | In the process of underground excavation, the surrounding rock is in a very complex stress environment, especially under the influence of its anisotropy, the occurrence of dynamic disaster is hidden. In this paper, the loading and unloading tests of sandstone in different principal stress directions were carried out by using the true triaxial unloading disturbed rock test system. The mechanical properties and failure characteristics of true triaxial under different principal stresses were studied, the energy evolution mechanism in other directions induced by loading and unloading of different principal stresses was analyzed. Results showed that under the influence of rock mass secondary stress anisotropy, during the cyclic loading and unloading process of the first principal stress, the strain in other directions shows opposite deformation. The volumetric strain compresses first and then expands, and the final volumetric strain shows a macroscopic phenomenon of expansion. When the third principal stress of high confining pressure rock mass is unloaded, the first principal stress produces a compression deformation, while the second and third principal stresses produce an expansion deformation. The deformation of the second principal stress is less than that of the third principal stress, and the deformation in unloading direction changes from linear elastic state to elastic-plastic nonlinear state. The accumulated energy of rock mass is a great difference between the first principal stress unloading and the third principal stress unloading. The energy variation characteristics of unloading in the dominant direction determine the energy accumulation and release law in the other two induced directions. The limit stored energy of the third principal stress unloading rock decreases, and the second principal stress accelerates the rock failure with the increase of the first principal stress, which verifies that the rock is easier to be destroyed by unloading than by loading. The higher the unloading rate of the third principal stress, the higher the energy released and the lower the dissipated energy, and the lower the energy density and total accumulated energy density in the unloading direction of rock mass. The main cause of dynamic accidents is the accumulation and release of energy in rock mass. The secondary anisotropy of rock mass has a great influence on the ultimate stored energy of rock mass. The study on the influence characteristics of three-dimensional loading and unloading secondary stress on the ultimate stored energy of rock mass provides a reference for preventing rock burst. |
| first_indexed | 2024-03-13T02:53:08Z |
| format | Article |
| id | doaj.art-0eafe765f74e46ec8cd7ff1202bd962c |
| institution | Directory Open Access Journal |
| issn | 0253-9993 |
| language | zho |
| last_indexed | 2024-03-13T02:53:08Z |
| publishDate | 2023-04-01 |
| publisher | Editorial Office of Journal of China Coal Society |
| record_format | Article |
| series | Meitan xuebao |
| spelling | doaj.art-0eafe765f74e46ec8cd7ff1202bd962c2023-06-28T08:10:18ZzhoEditorial Office of Journal of China Coal SocietyMeitan xuebao0253-99932023-04-014841502151510.13225/j.cnki.jccs.2022.07662022-0766Anisotropy and energy evolution mechanism of rock mass under true triaxial loading-unloadingWensong XU0Guangming ZHAO1Xiangrui MENG2Zhixi LIU3Chongyan LIU4Minjie QI5Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan 232001, ChinaLaboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan 232001, ChinaLaboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan 232001, ChinaLaboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan 232001, ChinaLaboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan 232001, ChinaLaboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan 232001, ChinaIn the process of underground excavation, the surrounding rock is in a very complex stress environment, especially under the influence of its anisotropy, the occurrence of dynamic disaster is hidden. In this paper, the loading and unloading tests of sandstone in different principal stress directions were carried out by using the true triaxial unloading disturbed rock test system. The mechanical properties and failure characteristics of true triaxial under different principal stresses were studied, the energy evolution mechanism in other directions induced by loading and unloading of different principal stresses was analyzed. Results showed that under the influence of rock mass secondary stress anisotropy, during the cyclic loading and unloading process of the first principal stress, the strain in other directions shows opposite deformation. The volumetric strain compresses first and then expands, and the final volumetric strain shows a macroscopic phenomenon of expansion. When the third principal stress of high confining pressure rock mass is unloaded, the first principal stress produces a compression deformation, while the second and third principal stresses produce an expansion deformation. The deformation of the second principal stress is less than that of the third principal stress, and the deformation in unloading direction changes from linear elastic state to elastic-plastic nonlinear state. The accumulated energy of rock mass is a great difference between the first principal stress unloading and the third principal stress unloading. The energy variation characteristics of unloading in the dominant direction determine the energy accumulation and release law in the other two induced directions. The limit stored energy of the third principal stress unloading rock decreases, and the second principal stress accelerates the rock failure with the increase of the first principal stress, which verifies that the rock is easier to be destroyed by unloading than by loading. The higher the unloading rate of the third principal stress, the higher the energy released and the lower the dissipated energy, and the lower the energy density and total accumulated energy density in the unloading direction of rock mass. The main cause of dynamic accidents is the accumulation and release of energy in rock mass. The secondary anisotropy of rock mass has a great influence on the ultimate stored energy of rock mass. The study on the influence characteristics of three-dimensional loading and unloading secondary stress on the ultimate stored energy of rock mass provides a reference for preventing rock burst.http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2022.0766true triaxial loading and unloadinganisotropyenergy accumulationrelease strain energy |
| spellingShingle | Wensong XU Guangming ZHAO Xiangrui MENG Zhixi LIU Chongyan LIU Minjie QI Anisotropy and energy evolution mechanism of rock mass under true triaxial loading-unloading Meitan xuebao true triaxial loading and unloading anisotropy energy accumulation release strain energy |
| title | Anisotropy and energy evolution mechanism of rock mass under true triaxial loading-unloading |
| title_full | Anisotropy and energy evolution mechanism of rock mass under true triaxial loading-unloading |
| title_fullStr | Anisotropy and energy evolution mechanism of rock mass under true triaxial loading-unloading |
| title_full_unstemmed | Anisotropy and energy evolution mechanism of rock mass under true triaxial loading-unloading |
| title_short | Anisotropy and energy evolution mechanism of rock mass under true triaxial loading-unloading |
| title_sort | anisotropy and energy evolution mechanism of rock mass under true triaxial loading unloading |
| topic | true triaxial loading and unloading anisotropy energy accumulation release strain energy |
| url | http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2022.0766 |
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