Dynamic characteristics of basalt fibre-reinforced polymer cement mortar bolts and its applicability for bolt defect detection

Zhao, Dongping; Wen, Sixun; Zhu, Long

doi:10.1016/j.jobe.2023.108218

Cited by 2 publications

(1 citation statement)

References 18 publications

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“…It is important to note that the wave velocity of B-1 anchor rod at 30 kN was slightly smaller than the wave velocity at 40 kN, with a difference of 11.61 m s −1 , accounting for 0.37% of the wave velocity at 40 kN. According to previous research results [39], this proportion fell within the acceptable range of error. In the absence of applied pull-out loads, the influence of size effect causes anchor rods embedded in thicker surrounding rock to have significantly lower wave velocities compared to those in thinner surrounding rock.…”

Section: Signal Processing Methodsmentioning

confidence: 49%

Investigation on the dynamic characteristics of anchor rods considering size effect and pull-out loads based on IIR-FDM

Sun,

Zhu,

Song

et al. 2024

Meas. Sci. Technol.

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When the surrounding rock of tunnel anchor bars has boundaries, the signals obtained from NDT of anchor rods will be simultaneously affected by size effects and pull-out loads, leading to potential misinterpretation of the test results. In order to accurately assess the anchorage quality of anchor rods under this interference, NDT and numerical simulations of anchor rods subjected to different anchorage quality were conducted under the influence of size effects and pull-out loads. A signal filtering method, which combines the infinite impulse response-finite difference method , was proposed for identify the impact of size effects. The study analyzed the variations in wave velocity and fundamental frequency of anchor rods with anchorage defects and intact anchor rods under the influence of size effects and pull-out loads. The results indicate that the IIR-FDM method, in comparison to the traditional wavelet method, provides better agreement between the calculated wave velocities and existing findings. With the increase of size effect, the wave velocity and amplitude ratio of the anchor rods decrease, and the fundamental frequency increases first and then decreases. As the working load on the anchor rods increases, the wave velocity initially decreases, then rises, while the fundamental frequency initially increases and then experiences a slight decrease. The presence of anchorage defect results in an increase in the wave velocity and amplitude ratio of the anchor rods, while causing a decrease in the fundamental frequency. This effect of defects on wave velocity and fundamental frequency is more pronounced at lower loads. The wave velocity after IIR-FDM processing has a small error with the simulated wave velocity, indicating the reliability of the processing method.

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Section: Signal Processing Methodsmentioning

confidence: 49%

Investigation on the dynamic characteristics of anchor rods considering size effect and pull-out loads based on IIR-FDM

Sun,

Zhu,

Song

et al. 2024

Meas. Sci. Technol.

View full text Add to dashboard Cite

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Analysis of progressive collapse disaster and its anchoring effectiveness in jointed rock tunnel

Zheng,

He,

Wang

et al. 2024

Num Anal Meth Geomechanics

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The complexity and variability of the structural distribution and combination characteristics of jointed rock masses make the response mechanism of tunnel rock collapse different, and there is a lack of systematic research on the existing perimeter rock instability mode and bolt support scheme. Based on numerical simulations of the block system structure of a nodular rock mass, the existing theory of bolt support is compared and analyzed to explore the scope of their respective applications. Combined with the spatial and temporal transport law of block instability, a new batch instability model of jointed rock tunnels is proposed, which reveals the progressive collapse catastrophe evolution mechanism of a collapsed interlocking block system after the instability of the key blocks and elucidates the coupling mechanism between the bolts and the block system structure as well as their anchoring effectiveness. Finally, for the actual tunnel project, the instability batches of the surrounding rock are identified, and the corresponding optimized design of the bolt support is presented, which has achieved good support effects. The research results can provide important theoretical guidance and practical engineering value for risk avoidance, disaster identification and targeted prevention and control of dangerous rock fall and chain collapse instability disasters in jointed rock body tunnels.

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Dynamic characteristics of basalt fibre-reinforced polymer cement mortar bolts and its applicability for bolt defect detection

Cited by 2 publications

References 18 publications

Investigation on the dynamic characteristics of anchor rods considering size effect and pull-out loads based on IIR-FDM

Investigation on the dynamic characteristics of anchor rods considering size effect and pull-out loads based on IIR-FDM

Analysis of progressive collapse disaster and its anchoring effectiveness in jointed rock tunnel

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