Failure mechanism and stability analysis of an open-pit slope under excavation unloading conditions
Excavation unloading significantly contributes to rock slope failure in an open-pit mine. At present, there is no relevant theoretical study on the failure mechanism of the rock slope under excavation unloading. Therefore, in this study, based on the theory of fracture mechanics, the expression of t...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-01-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2023.1109316/full |
| _version_ | 1797948150591258624 |
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| author | Jianming Wang Jianming Wang Zihan Zhou Chong Chen Huan Wang Zhonghui Chen |
| author_facet | Jianming Wang Jianming Wang Zihan Zhou Chong Chen Huan Wang Zhonghui Chen |
| author_sort | Jianming Wang |
| collection | DOAJ |
| description | Excavation unloading significantly contributes to rock slope failure in an open-pit mine. At present, there is no relevant theoretical study on the failure mechanism of the rock slope under excavation unloading. Therefore, in this study, based on the theory of fracture mechanics, the expression of the stress intensity factor at the crack tip on the rock mass at the vertical distance, h, from the slope top under excavation unloading is derived, the calculation method of the crack initiation angle is given, the expression of the ultimate safe height of the slope under unloading is obtained, and the ratio of the fracture toughness of the slope rock mass to the composite stress intensity factor at the crack tip on the rock mass is defined as the slope stability factor, which is verified by an engineering example. The results show that the crack initiation angle decreased when crack inclination was increased, and the crack initiation angle increased when the side-pressure coefficient, slope angle, and friction coefficient were increased. The ultimate safety height of the slope decreased first and then increased with the increase in the crack angle, and it was approximately linear with the crack length and inversely proportional with the slope angle. The stability coefficient calculated by this method is the same as that calculated by the limit equilibrium method and is small, which indicates the accuracy and rationality of this method. Results in this study can provide a theoretical basis for understanding and controlling the slope collapse disaster induced by excavation unloading. |
| first_indexed | 2024-04-10T21:39:43Z |
| format | Article |
| id | doaj.art-e1b569dec1964249a7c24ab98f7100ca |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-10T21:39:43Z |
| publishDate | 2023-01-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-e1b569dec1964249a7c24ab98f7100ca2023-01-19T07:09:18ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632023-01-011110.3389/feart.2023.11093161109316Failure mechanism and stability analysis of an open-pit slope under excavation unloading conditionsJianming Wang0Jianming Wang1Zihan Zhou2Chong Chen3Huan Wang4Zhonghui Chen5Ansteel Beijing Research Institute, Beijing, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology, Beijing, ChinaDepartment of Civil Engineering, Tsinghua University, Beijing, ChinaAnsteel Beijing Research Institute, Beijing, ChinaAnsteel Beijing Research Institute, Beijing, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology, Beijing, ChinaExcavation unloading significantly contributes to rock slope failure in an open-pit mine. At present, there is no relevant theoretical study on the failure mechanism of the rock slope under excavation unloading. Therefore, in this study, based on the theory of fracture mechanics, the expression of the stress intensity factor at the crack tip on the rock mass at the vertical distance, h, from the slope top under excavation unloading is derived, the calculation method of the crack initiation angle is given, the expression of the ultimate safe height of the slope under unloading is obtained, and the ratio of the fracture toughness of the slope rock mass to the composite stress intensity factor at the crack tip on the rock mass is defined as the slope stability factor, which is verified by an engineering example. The results show that the crack initiation angle decreased when crack inclination was increased, and the crack initiation angle increased when the side-pressure coefficient, slope angle, and friction coefficient were increased. The ultimate safety height of the slope decreased first and then increased with the increase in the crack angle, and it was approximately linear with the crack length and inversely proportional with the slope angle. The stability coefficient calculated by this method is the same as that calculated by the limit equilibrium method and is small, which indicates the accuracy and rationality of this method. Results in this study can provide a theoretical basis for understanding and controlling the slope collapse disaster induced by excavation unloading.https://www.frontiersin.org/articles/10.3389/feart.2023.1109316/fullexcavation unloadingcrack initiation anglestress intensity factorsafety factorrock mass |
| spellingShingle | Jianming Wang Jianming Wang Zihan Zhou Chong Chen Huan Wang Zhonghui Chen Failure mechanism and stability analysis of an open-pit slope under excavation unloading conditions Frontiers in Earth Science excavation unloading crack initiation angle stress intensity factor safety factor rock mass |
| title | Failure mechanism and stability analysis of an open-pit slope under excavation unloading conditions |
| title_full | Failure mechanism and stability analysis of an open-pit slope under excavation unloading conditions |
| title_fullStr | Failure mechanism and stability analysis of an open-pit slope under excavation unloading conditions |
| title_full_unstemmed | Failure mechanism and stability analysis of an open-pit slope under excavation unloading conditions |
| title_short | Failure mechanism and stability analysis of an open-pit slope under excavation unloading conditions |
| title_sort | failure mechanism and stability analysis of an open pit slope under excavation unloading conditions |
| topic | excavation unloading crack initiation angle stress intensity factor safety factor rock mass |
| url | https://www.frontiersin.org/articles/10.3389/feart.2023.1109316/full |
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