@inproceedings{a7d43e05d8cf4320b09e4f1b2d0ce819,
title = "Rock bolt integrity evaluation in tunnelling using ultrasonic NDT techniques",
abstract = "Rock bolts play a crucial role in the reinforcement of Single-shell tunnels and rock slopes as rock bolts become a main support system. Numerical and experimental studies are performed to evaluate the integrity of rock bolts encapsulated by grouting paste using a transmission method of ultrasonic guided waves. Numerical simulation shows that the optimal frequency range is 20-70 kHz in the first longitudinal L(1) mode for the rock bolt NDT system. Analytical and experimental results represent the velocities of the ultrasonic guided wave increase with increase in the defect ratio. This study demonstrates that the transmission method of ultrasonic guided waves may be a valuable tool for the evaluation of the rock bolt integrity.",
author = "Lee, {J. S.} and Kim, {H. J.} and Lee, {I. M.} and Han, {S. I.} and Lee, {Y. J.}",
year = "2007",
language = "English",
isbn = "0415408075",
series = "{"}Proceedings of the 33rd ITA-AITES World Tunnel Congress - Underground Space - The 4th Dimension of Metropolises{"}",
pages = "321--326",
booktitle = "Proceedings of the 33rd ITA-AITES World Tunnel Congress - Underground Space - The 4th Dimension of Metropolises",
note = "33rd ITA-AITES World Tunnel Congress - Underground Space - The 4th Dimension of Metropolises, WTC 2007 ; Conference date: 05-05-2007 Through 10-05-2007",
}