Experimental and Numerical Study on the Interface Behaviour Between the Rock Bolt and Bond Material

Yokota, Yasuhiro; Zhao, Zhiye; Nie, Wen; Date, Kensuke; Iwano, Kaoru; Okada, Yuko

doi:10.1007/s00603-018-1629-4

Cited by 44 publications

(13 citation statements)

References 8 publications

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“…Many studies of bolt design (i.e. height, spacing, reinforcing angle) concerned the problem (Yokota et al, 2018); thus, the problems were not considered in the paper and standard armature was used.…”

Section: The Research Methodsmentioning

confidence: 99%

Laboratory studies of a high-strength roof bolting by means of self-extending mixtures

Sakhno¹,

Sakhno²,

Isaienkov³

et al. 2019

Min. miner. depos.

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Purpose is to analyze parameters of a new method to fasten roof bolts with the help of nonadhesive mixtures extending while hardening along with the development of high expansion pressures.Methods. The research, concerning forces applied while fastening roof bolts by means of self-extending mixtures, has been carried out under full-scale laboratory conditions using pressing-in method. Rock mass was simulated by means of concrete in plastic and metal forms, and steel pipes. The latter simulated ultimate rigidness conditions. Roof bolts were simulated by means of reinforcement steel fragments. In the context of the research, bolt diameters varied from 8 to 32 mm, and borehole diameters varied from 26 to 43 mm. Hydraulic 50-ton press was used for the tests. The testing results were applied to obtain regressive dependences of bolt fastening efforts in terms of different ratios between roof bolt diameter, borehole diameter, and incapsulation depth. Mine experiments concerning efforts to fasten Rockbolt System AG roof bolts of J64-27 type to strengthen chamber 1 of level 3 in Velychka mine were performed using a method of static bolt extraction. Hydraulic extraction device was equipped by ZEPWN CL 18T sensor and CL 162z-DW recorder.Findings. It has been proved experimentally that operation mechanism of the roof bolts, fastened by means of selfextending mixtures during hydration hardening, is close to the modern energy absorbing bolts. Bolt diameterborehole diameter ratio range, when ultimate effort of bolt fastening by means of extending mixtures is achieved, has been determined. Functional connection between the efforts to fasten roof bolts, using extending mixtures, and diameters of borehole and the roof bolt has been identified as well as linear connection between incapsulation depth and bearing capacity of the roof bolt. Originality.A new concept to fasten roof bolts with the help of nonadhesive technique owing to their quazistatic compression between borehole walls, taking place as a result of hydration self-extension of mixtures which can achieve 30 -50 MPa pressures under the conditions of zero deformations, has been developed. Regularities in the variation of efforts to fasten bolts, using the technique, depending upon roof bolt -fastening mixture -rock mass system geometry have been determined. Practical implications.The results can be used to calculate parameters of roof bolting with high bearing capacity under the conditions of large deformations. The proposed fastening method may be implemented in mine workings.

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Section: The Research Methodsmentioning

confidence: 99%

Laboratory studies of a high-strength roof bolting by means of self-extending mixtures

Sakhno¹,

Sakhno²,

Isaienkov³

et al. 2019

Min. miner. depos.

View full text Add to dashboard Cite

show abstract

“…It is believed that the experimental approach is more credible. This is because compared with the experimental approach, the analytical simulation and numerical simulation usually relied on a number of assumptions (Yokota et al, 2019). Whether those assumptions are reasonable is doubted.…”

Section: Discussionmentioning

confidence: 99%

Analysis on the Shear Stress Propagation Mechanism in the Rock Reinforcement System

Chen

Zhao

et al. 2022

Front. Earth Sci.

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Rock reinforcement is significant in maintaining the stability of excavated structures, such as tunnels and underground roadways. However, shear failure in the rock reinforcement system, especially the shear failure at the rock reinforcement bolt surface, induces a threat to the rock reinforcement system. To reveal the shear stress (SS) propagation mechanism in the rock reinforcement system, this article conducted a literature review. First, the investigation approaches that were used by previous researchers to study the SS propagation were summarized. The advantages and disadvantages of experimental tests, analytical simulation, and numerical simulation were compared and analyzed. Then, the SS propagation process in the rock reinforcement system was presented. Two typical SS propagation modes were explained. More attention was given to the SS propagation mode in which the maximum SS propagates from the external end of rock reinforcement bolts to the internal end of rock reinforcement bolts. After that, a discussion section was given. In the discussion section, the significance of the SS propagation was further emphasized. Moreover, the limitations in the analytical simulation and numerical simulation were indicated. It is concluded that when studying the SS propagation mechanism of rock reinforcement bolts, combining experimental tests, analytical simulation, and numerical simulation is a better choice. This study is beneficial for revealing the SS propagation mechanism of the rock reinforcement system.

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“…Evaluation of the quality of the anchor shoring operation and the behavior of the rock mass around the excavations can be performed based on monitoring, which includes measurements of the following: excavation roof loads such as dynamometers [9], instrumented anchors [10], pressure pads [11], dynamometer discs [12], stratification of the roof rocks [13], sloughing of the roof layers using a borehole endoscope, aerometric soda, radiometric method [14], convergence of the excavation [15] and many others. The effectiveness of anchor shoring in mine conditions most often includes activities related to verifying the correctness of its installation in the excavation.…”

Section: Introductionmentioning

confidence: 99%

Non-Destructive Acoustical Rock Bolt Testing System with Intelligent Filtering in Salt Mine ‘Wieliczka’

et al. 2021

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This article presents the application of a self-excited acoustic SAS system for non-destructive testing (NDT) for roof-bolt housings in laboratory and real mine conditions. The proposed system with a filtering mechanism was applied to the J64-27 composite anchors. The conducted tests allowed successful confirmation of the usefulness of the system in the detection of rod defects, damage of the mechanism coupling the anchor to the rock mass and testing of the stress state of the anchor itself. The proposed filtering system allowed eliminating the effect of jump change of frequency in the limit cycle of self-excited system. The proposed method is a novel solution for safety diagnostics of bolt housings in mining applications.

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Experimental and Numerical Study on the Interface Behaviour Between the Rock Bolt and Bond Material

Cited by 44 publications

References 8 publications

Laboratory studies of a high-strength roof bolting by means of self-extending mixtures

Laboratory studies of a high-strength roof bolting by means of self-extending mixtures

Analysis on the Shear Stress Propagation Mechanism in the Rock Reinforcement System

Non-Destructive Acoustical Rock Bolt Testing System with Intelligent Filtering in Salt Mine ‘Wieliczka’

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