Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Prestress Loss Mechanism and Constitutive Model of an Anchored Joint Rock Mass Under Low-frequency Fatigue Loading
https://orcid.org/0000-0002-8335-5469
Abstract Cyclical impact loads will transform into low-frequency fatigue loads during propagation; furthermore, the long-term disturbance of such loads induces the prestress loss of far-field anchored joint rock masses (AJRMs). Laboratory tests of AJRMs under different fatigue shear loads were conducted. The yield pattern of anchors, failure pattern of rock blocks and failure mechanism of joints were analysed. The prestress loss characteristics of anchors were studied in great detail. Based on the experimental results, a prestress loss constitutive model of anchors was explored. The results revealed that the morphology of the yielded zone of the anchor is z-shaped, while the failure patterns of the anchored rock blocks were mainly body cracking, and the stable rock blocks presented exfoliation of the cement mortar. In addition, microfissure growth and macrocrack nucleation under shear forces and fatigue forces resulted in the formation of macroscopic cracks and joint block spalling. A wavy ascent stage in the prestress loss caused by the fatigue load occurred, and the prestress loss increment and rate increased gradually as the fatigue loads increased. The Nishihara model and an elastic body were coupled to establish a coupled model that considers the influence of fatigue load, and a prestress relaxation equation of anchors was derived. When compared with data measured during a real engineering project, the results of the prestress relaxation equation exhibited good accuracy.
Highlights The influence of the fatigue conditions on the prestress loss characteristics of anchors was analysed.The development and aggregation of cracks that initiate along the dominant direction of the fatigue force leads to the loss of the bearing capacity of the joint.A new constitutive model was developed to describe the rock-anchor coupling under fatigue loading.
Prestress Loss Mechanism and Constitutive Model of an Anchored Joint Rock Mass Under Low-frequency Fatigue Loading
https://orcid.org/0000-0002-8335-5469
Abstract Cyclical impact loads will transform into low-frequency fatigue loads during propagation; furthermore, the long-term disturbance of such loads induces the prestress loss of far-field anchored joint rock masses (AJRMs). Laboratory tests of AJRMs under different fatigue shear loads were conducted. The yield pattern of anchors, failure pattern of rock blocks and failure mechanism of joints were analysed. The prestress loss characteristics of anchors were studied in great detail. Based on the experimental results, a prestress loss constitutive model of anchors was explored. The results revealed that the morphology of the yielded zone of the anchor is z-shaped, while the failure patterns of the anchored rock blocks were mainly body cracking, and the stable rock blocks presented exfoliation of the cement mortar. In addition, microfissure growth and macrocrack nucleation under shear forces and fatigue forces resulted in the formation of macroscopic cracks and joint block spalling. A wavy ascent stage in the prestress loss caused by the fatigue load occurred, and the prestress loss increment and rate increased gradually as the fatigue loads increased. The Nishihara model and an elastic body were coupled to establish a coupled model that considers the influence of fatigue load, and a prestress relaxation equation of anchors was derived. When compared with data measured during a real engineering project, the results of the prestress relaxation equation exhibited good accuracy.
Highlights The influence of the fatigue conditions on the prestress loss characteristics of anchors was analysed.The development and aggregation of cracks that initiate along the dominant direction of the fatigue force leads to the loss of the bearing capacity of the joint.A new constitutive model was developed to describe the rock-anchor coupling under fatigue loading.
Prestress Loss Mechanism and Constitutive Model of an Anchored Joint Rock Mass Under Low-frequency Fatigue Loading
https://orcid.org/0000-0002-8335-5469
Abstract Cyclical impact loads will transform into low-frequency fatigue loads during propagation; furthermore, the long-term disturbance of such loads induces the prestress loss of far-field anchored joint rock masses (AJRMs). Laboratory tests of AJRMs under different fatigue shear loads were conducted. The yield pattern of anchors, failure pattern of rock blocks and failure mechanism of joints were analysed. The prestress loss characteristics of anchors were studied in great detail. Based on the experimental results, a prestress loss constitutive model of anchors was explored. The results revealed that the morphology of the yielded zone of the anchor is z-shaped, while the failure patterns of the anchored rock blocks were mainly body cracking, and the stable rock blocks presented exfoliation of the cement mortar. In addition, microfissure growth and macrocrack nucleation under shear forces and fatigue forces resulted in the formation of macroscopic cracks and joint block spalling. A wavy ascent stage in the prestress loss caused by the fatigue load occurred, and the prestress loss increment and rate increased gradually as the fatigue loads increased. The Nishihara model and an elastic body were coupled to establish a coupled model that considers the influence of fatigue load, and a prestress relaxation equation of anchors was derived. When compared with data measured during a real engineering project, the results of the prestress relaxation equation exhibited good accuracy.
Highlights The influence of the fatigue conditions on the prestress loss characteristics of anchors was analysed.The development and aggregation of cracks that initiate along the dominant direction of the fatigue force leads to the loss of the bearing capacity of the joint.A new constitutive model was developed to describe the rock-anchor coupling under fatigue loading.
Prestress Loss Mechanism and Constitutive Model of an Anchored Joint Rock Mass Under Low-frequency Fatigue Loading
Zhong, Zhu (Autor:in) / Li, Yongqi (Autor:in) / Huang, Da (Autor:in)
2022
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
BKL:
38.58
Geomechanik
/
56.20
Ingenieurgeologie, Bodenmechanik
/
38.58$jGeomechanik
/
56.20$jIngenieurgeologie$jBodenmechanik
RVK:
ELIB41
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