Analytical Formulation on the Mechanical Behavior of Anchorage Interface for Full-Length Bonded Bolt

2012 ◽  
Vol 166-169 ◽  
pp. 3254-3257
Author(s):  
Bo Liu ◽  
Li Huang ◽  
Dong Yang Li
Keyword(s):  
Local Deformation ◽  
Full Length ◽  
Mathematics Model ◽  
Continuous Change ◽  
Pull Out ◽  
Interface Bond Strength ◽  
Three Stages ◽  
Interface Bond ◽  
Softening Stage ◽  
Elastic Stage

Based on the local deformation theory, we study the mechanics behavior of anchorage interface of full-length bonded rock bolt by using a mathematics model (tri-linear model). With pull-out load increasing, the changing process of anchorage interface of full-length bonded bolt is divided into three stages in this paper: elastic stage, plastic softening stage and crack slipping stage. It is found that in the state of elastic, axis force decreases rapidly with bolt depth increasing, and when pull-out load is greater than elastic ultimate load, attenuation degree will slow for the occurring of interface plastic softening and crack slipping in the top of bolt. The result indicates that the continuous change of axis force with bolt depth reflects that the bolt interface bond strength changes with the increase of pulling load.

scholarly journals Analysis of the Elastic-Plastic Theoretical Model of the Pull-Out Interface between Geosynthetics and Tailings

2020 ◽  
Vol 2020 ◽  
pp. 1-22
Author(s):  
Changbo Du ◽  
Fu Yi
Keyword(s):  
Shear Stress ◽  
Progressive Failure ◽  
Shear Stiffness ◽  
Interface Shear ◽  
Interface Shear Stress ◽  
Transition Stage ◽  
Elastic Plastic ◽  
Pull Out ◽  
Softening Stage ◽  
Elastic Stage

Aiming at the strain-hardening and strain-softening phenomena between geosynthetics and tailings during pull-out tests, bilinear and trilinear shear stress-displacement softening models were proposed. The pull-out process of the hardening reinforcement was divided into the elastic stage, elastic-hardening transition stage, and pure hardening stage. The pull-out process of the softened reinforcement was divided into the elastic stage, elastic-softening transition stage, pure softening stage, softening-residual transition stage, and pure residual stage. The expressions of the interface tension, shear stress, and displacement at the different stages under a pull-out load were derived through the interface basic control equation. At the same time, the evolution law of the interface shear stress at different pull-out stages was analysed, and the predicted results of the two elastic-plastic models were compared with the experimental results. The results show that the predicted results are in good agreement with the experimental data, which verifies the validity of the proposed two elastic-plastic models for the progressive failure analysis of reinforcement at the pull-out interface. During the process of pull-out, the transition stage is not obvious. When the reinforcement is in the elastic stage, the nonlinearity and maximum value of the interface shear stress increase with an increase in the elastic shear stiffness, while the tensile stiffness shows the opposite trend. When the reinforcement is in the hardening or softening stage, the larger the hardening (softening) shear stiffness is, the larger the change range of shear stress is and the more obvious the hardening (softening) characteristics of the reinforcement are. The results comprehensively reflect the progressive failure of reinforcement-tailing interfaces with different strain types and provide theoretical support for the study of the interface characteristics of geosynthetic-reinforced tailings.

Interface bond strength performance of overlap joints within the corrugated pipes used in prefabricated bridges

2022 ◽  
pp. 136943322110723
Author(s):  
Yasir Ibrahim Shah ◽  
Zhijian Hu ◽  
Pengfei Yao
Keyword(s):  
Bond Strength ◽  
High Strength ◽  
Influential Factors ◽  
Displacement Curve ◽  
Anchorage Length ◽  
Bond Performance ◽  
Pull Out ◽  
Interface Bond Strength ◽  
Grouting Reinforcement ◽  
Interface Bond

This paper presents an experimental study of a novel composite structure used in prefabricated bridges. Corrugated pipes were used to improve the interface bond performance of the structure because of their excellent stiffening effect on the grouting material. Interface bond performance of overlap joints within corrugated pipes was explored by the load-displacement curve and load-strain curves. Ultra-High Performance Concrete (UHPC) and high-strength mortar were used as grouting materials. The diameter of steel bars, UHPC, high-strength mortar, strength grades of surrounded concrete, anchorage length, the diameter of the corrugated pipe, and lap length was taken as influential factors. Twenty specimens were designed for the pull-out test by using a larger cover thickness. The failure modes and the influence of different influential factors on the interface bond strength of each specimen were analyzed. The results show that the bond performance between UHPC and reinforcement was better than that of high-strength mortar and normal concrete, which can effectively improve the bond strength and reduce the basic anchorage length of reinforcement besides the design size of prefabricated members. In addition, the differences in anchorage length and lap length between the corrugated pipe grouting reinforcement were compared to the different specifications and prefabricated concrete members. Combined with the test phenomenon and analysis results, it is suggested that the anchorage length and lap length of connecting reinforcement should be reconsidered. Furthermore, the grouting effect under different diameters of corrugated pipe and reinforcement were compared. It is recommended that the corrugated pipe diameter should be four times that of the overlapping grouting reinforcement.

Finite Element Stress Analysis of a Push-Out Test Part 1: Fixed Interface Using Stress Compatible Elements

1992 ◽  
Vol 114 (1) ◽  
pp. 111-118 ◽  
Author(s):  
A. Shirazi-Adl
Keyword(s):  
Boundary Conditions ◽  
Stress Analysis ◽  
Dissimilar Materials ◽  
Factors Affecting ◽  
Pull Out ◽  
Interface Bond Strength ◽  
Fixed Interface ◽  
Compatible Elements ◽  
Interface Bond ◽  
Push Out

In this first part of a two-part paper, interelement stress compatible finite elements are developed and used to perform the stress analysis of a push-out test with a fixed interface. In the formulation, the required continuity of some of the stresses along either a specific interface or all interelement interfaces is enforced by a penalty procedure. The model is axisymmetric and consists of two cylinders attached to each other through the interface. Various relative material properties and boundary conditions are simulated in order to examine their effects on the interface stresses. Both loadings of axial compression force and axial torque are considered. The predicted results exhibit identical interelement stresses and displacements even when highly dissimilar materials are used. They also exhibit a complex state of interface stresses which depend on the geometry, material arrangement, boundary conditions, and loading. The variation of the shear stress is often highly nonuniform and the radial normal stresses are likely to be large. The present results, therefore, disagree with the common assumptions made in the pull-out tests in the orthopaedic applications. Finally, stress analysis of a number of possible testing configurations could lead to the design of an optimal pull-out test which maximizes the usefulness of the measured results in terms of the interface bond strength and factors affecting it.

Bending Toughness of Zinc Phosphate Steel Fiber Reinforced Concrete before and after Corrosion

2010 ◽  
Vol 168-170 ◽  
pp. 1762-1766
Author(s):  
Min Sun ◽  
Di Jiang Wen ◽  
Peng Xie
Keyword(s):  
Reinforced Concrete ◽  
Zinc Phosphate ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Before And After ◽  
Interface Bond Strength ◽  
Interface Bond

The interface bond between steel fibers and concrete matrix is the key of carrying capacity of steel fiber reinforced concrete(SFRC). In marine tidal fluctuation zone and splashed area, steel fibers will be rusty, and the bending toughness of SFRC was weakened. In this study, we tried to improve corrosion resistance of steel fiber and the interface bond strength by depositing zinc phosphate coating on steel fiber. These zinc phosphate steel fiber reinforced concrete(ZSFRC) have higher anti-corrosion ability. After corrosion they still have higher bending toughness than common SFRC.

scholarly journals Experimental Study on Bond-Slip Behavior of Bamboo Bolt-Modified Slurry Interface under Pull-Out Load

2018 ◽  
Vol 2018 ◽  
pp. 1-23 ◽  
Author(s):  
Wei Lu ◽  
Dong Zhao ◽  
Xiao-fei Mao ◽  
Yu Ai
Keyword(s):  
Axial Direction ◽  
Impact Factors ◽  
Slip Model ◽  
Distribution Law ◽  
Bond Slip ◽  
Pull Out ◽  
Control Interface ◽  
Bolt Diameter ◽  
Interface Bond

This paper presents an analysis of bamboo bolt-modified slurry interfaces based on 26 in situ axial pull-out tests intended to highlight the mechanical behavior of interface under a fracture mode. Three impact factors are analyzed: anchorage length, bolt diameter, and bolt hole diameter, using the same materials of bamboo and modified slurry. The result shows that the interface between the bamboo bolt and anchoring agent is the control interface of an anchorage system, and the local behavior of the interface involves four stages: elastic, soften, friction, and decoupling. Distribution law and change trend of slippage, stress, and strain of anchoring interface along with the axial direction of an anchor bolt were analyzed. The result shows that there is effective anchoring length limit in this kind of interface, and that the complete decoupling phenomenon should not be neglected. Through a comparative analysis of the existing bond-slip model and interface bond-slip curve, and considering the correspondence of the strain-slip curve and trilinear bond-slip model simultaneously, a modified trilinear bond-slip model has been proposed. The friction section of this model is limited, and shearing stress in the complete decoupling section is zero.

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