| Autor: |
Han, Yafeng, Liu, Xinrong, Liu, Mingwei, Xu, Bin, Deng, Zhiyun, Zhou, Xiaohan, Zhang, Gang, Lai, Guoshen |
| Předmět: |
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| Zdroj: |
Rock Mechanics & Rock Engineering; Jun2023, Vol. 56 Issue 6, p4379-4404, 26p |
| Abstrakt: |
To investigate the effects of interface roughness on the pull-out performance and stability of a tunnel-type anchorage (TTA) installed in soft rock, tensile load tests are performed with model plug bodies with different surface roughnesses installed in soft rock model materials in a rectangle chamber with digital image correlation (DIC) capability. From the model tests, it is observed that the ultimate bearing capacity of a TTA decreases gradually with decreasing interface roughness. A TTA with rough interface successively goes through four states during loading, including linear elastic deformation, slow nonlinear deformation, plastic deformation and failure. Nevertheless, a TTA with low interface roughness directly enters a hardened state after undergoing linear elastic deformation. Additionally, the load when a TTA enters the hardened state decreases as the interface roughness decreases. The failure mode of TTA installed in soft rock is not a single rock mass failure or interface slipping failure, but gradually evolves from a single rock mass failure (or interface slipping and debonding) to a dual failure of rock mass failure and interface slipping and debonding. Nevertheless, whether rock mass failure or interface failure occurs first depends on the interface roughness. With a decrease in the interface roughness, a TTA installed in soft rock changes from a failure order of shear (or tensile‒shear) failure of the surrounding rock near the back end of the plug body crown → interface slipping and debonding → the tensile‒shear and tensile failure of the surrounding rock near the middle front end of the crown to the failure order of interface slipping and debonding → tensile‒shear failure of the surrounding rock near the front end of the crown → the tensile failure of the surrounding rock near the back end crown. Additionally, an interface with higher surface roughness mainly produces mixed failure characterized by the shear of the convex body of the surface and the soil particles near the convex body during slipping, while an interface with lower surface roughness produces a single failure characterized by the shear of soil particles. Highlights: This paper focuses on the effects of the plug body surface roughness on the pullout performance and failure characteristics of tunnel-type anchorages (TTAs) in soft rock. The full process of rock mass fracture and TTA instability under different plug body surface roughness conditions is reproduced in simulated models. Relative slip between rock mass and plug body decreases with the increases of interface roughness, which leads to the expansion of rock mass bearing range. The failure of TTA contains rock mass fracture and interface slip-debonding, while the order of occurrence is closely related to the interface roughness. The convex body of the interface and the soil body next to the convex body will be sheared during slipping of the high roughness interface. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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