Review of non-destructive methods for rock bolts condition evaluation

B Lama, M Momayez - Mining, 2023 - mdpi.com
Rock bolts are one of the most effective and conventional support techniques widely used in
underground mining and tunneling operations to stabilize excavations and jointed rock …

Application of time domain reflectometer for detecting necking defects in bored piles

JS Lee, JU Song, WT Hong, JD Yu - NDT & E International, 2018 - Elsevier
This paper presents a non-destructive method for detecting necking defects in bored piles
using electromagnetic waves. Small-scale laboratory experiments are conducted with a …

Non-destructive method for evaluating local integrity of model piles using electromagnetic waves

D Lee, JD Yu, S Jeong, G Park, JS Lee - NDT & E International, 2024 - Elsevier
The objective of this study is to suggest a more accurate integrity estimation method in
drilled shafts using electromagnetic waves propagating through transmission lines. Model …

Smart sensing using electromagnetic waves for inspection of defects in rock bolts

JD Yu, JS Lee - Sensors, 2020 - mdpi.com
The stability of tunnels and rock slopes is adversely affected by defects in rock bolts. This
study investigates the suitability of the smart sensing method using electromagnetic waves …

Horizontally elongated time domain reflectometry system for evaluation of soil moisture distribution

DJ Kim, JD Yu, YH Byun - Sensors, 2020 - mdpi.com
The objective of this study was to develop a horizontally elongated time domain
reflectometry (HETDR) system to evaluate the water content in nonuniformly wetted soils …

[HTML][HTML] Nondestructive evaluation of grout defect in rock bolt using electromagnetic waves

JS Lee, JD Yu - Developments in the Built Environment, 2024 - Elsevier
This study aims to inspect grout defects in rock bolts using electromagnetic (EM) waves. The
experiments are conducted using one intact rock bolt and eight defective rock bolts with …

A Novel Method for Integrity Assessment of Soil-Nailing Works with Actively Heated Fiber-Optic Sensors

J Wang, SQ Lin, DY Tan, JH Yin, HH Zhu… - Journal of Geotechnical …, 2024 - ascelibrary.org
Soil nailing has become a common method for improving slope stability due to its cost-
effectiveness and easy installation. However, concerns have been arisen regarding the …

Nondestructive integrity evaluation of soil nails using longitudinal waves

JD Yu, NY Kim, JS Lee - Journal of Geotechnical and …, 2018 - ascelibrary.org
Structural failures of soil-nailed structures occasionally occur due to the poor integrity of soil
nails. The objective of this study was to evaluate soil nail integrity by estimating the installed …

Circular time-domain reflectometry system for monitoring bridge scour depth

JD Yu, JS Lee, HK Yoon - Marine Georesources & Geotechnology, 2020 - Taylor & Francis
Sediment has a severe effect on bridge stability, and time-domain reflectometry (TDR) is a
suitable method for assessing scour depth. This paper presents a fundamental study to …

Non-destructive method for evaluating grouted ratio of soil nail using electromagnetic wave

JS Lee, JD Yu - Journal of Nondestructive Evaluation, 2019 - Springer
Although soil nails have been widely used for stabilizing slopes, they are often only partially
grouted. Thus, grouted ratio of soil nails should be evaluated to prevent landslides. The …