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Macro–Meso Fracture and Instability Behaviors of Hollow-Cylinder Granite Containing Fissures Subjected to Freeze–Thaw–Fatigue Loads
Abstract Rock structural deterioration induced by coupled freeze–thaw and stress disturbance are a great concern for jointed rock mass during rock constructions in cold regions. Previous studies focused on fracture evolution of intact rock or flawed rock under freeze–thaw–static loads, but the coupling effect of freeze–thaw and cyclic loads on the pre-flawed hollow-cylinder rock is not well understood. This work investigated the influence of freeze–thaw on rock microstructure change and fatigue mechanical behaviors. Testing results show that rock strength, volumetric strain, and lifetime decrease with increasing F–T number. The stiffness degradation caused by cyclic loads is also impacted by the previous freeze–thaw damage. Additionally, the AE ring count and energy count decrease with the increase of F–T treatment. Large fracture signals are captured for rock that has smaller F–T cycles and at the stress-increasing moment. The AE b-value increases with F–T cycles, and it decreases rapidly near rock failure. Spectral analysis indicates that large-scaled cracking is prone to form for a sample having high F–T cycles. Moreover, 2D CT images reveal the differential crack network pattern at rock bridge segments and how it is affected by the previous freeze–thaw damage. The crack coalescence and hole collapse patterns and the associated structural deterioration of the rock bridge segment are obviously influenced by the F–T treatment.
Highlights Fracture behaviors of pre-flawed hollow-cylinder granite under freeze-thaw-fatigue loads were analyzed.Cyclic freeze-thaw weathering influences rock microstructure and geomechanical properties.Acoustic emission parameters and spectral analysis reveals the impact of F-T on rock progressive failure.The crack coalescence and hole collapse patterns are obviously influenced by the F-T treatment.
Macro–Meso Fracture and Instability Behaviors of Hollow-Cylinder Granite Containing Fissures Subjected to Freeze–Thaw–Fatigue Loads
Abstract Rock structural deterioration induced by coupled freeze–thaw and stress disturbance are a great concern for jointed rock mass during rock constructions in cold regions. Previous studies focused on fracture evolution of intact rock or flawed rock under freeze–thaw–static loads, but the coupling effect of freeze–thaw and cyclic loads on the pre-flawed hollow-cylinder rock is not well understood. This work investigated the influence of freeze–thaw on rock microstructure change and fatigue mechanical behaviors. Testing results show that rock strength, volumetric strain, and lifetime decrease with increasing F–T number. The stiffness degradation caused by cyclic loads is also impacted by the previous freeze–thaw damage. Additionally, the AE ring count and energy count decrease with the increase of F–T treatment. Large fracture signals are captured for rock that has smaller F–T cycles and at the stress-increasing moment. The AE b-value increases with F–T cycles, and it decreases rapidly near rock failure. Spectral analysis indicates that large-scaled cracking is prone to form for a sample having high F–T cycles. Moreover, 2D CT images reveal the differential crack network pattern at rock bridge segments and how it is affected by the previous freeze–thaw damage. The crack coalescence and hole collapse patterns and the associated structural deterioration of the rock bridge segment are obviously influenced by the F–T treatment.
Highlights Fracture behaviors of pre-flawed hollow-cylinder granite under freeze-thaw-fatigue loads were analyzed.Cyclic freeze-thaw weathering influences rock microstructure and geomechanical properties.Acoustic emission parameters and spectral analysis reveals the impact of F-T on rock progressive failure.The crack coalescence and hole collapse patterns are obviously influenced by the F-T treatment.
Macro–Meso Fracture and Instability Behaviors of Hollow-Cylinder Granite Containing Fissures Subjected to Freeze–Thaw–Fatigue Loads
Wang, Yu (author) / Song, Zhengyang (author) / Mao, Tianqiao (author) / Zhu, Chun (author)
2022
Article (Journal)
Electronic Resource
English
BKL:
38.58
Geomechanik
/
56.20
Ingenieurgeologie, Bodenmechanik
/
38.58$jGeomechanik
/
56.20$jIngenieurgeologie$jBodenmechanik
RVK:
ELIB41
| Elsevier | 2024