RTRI REPORT December 2001
ANOTHER PAPER

Non-destructive Evaluation System of Tunnel Concrete Lining using Wavelet Transform Analysis and New Acoustic Tapping Measurement

Hideaki ENOMOTO, Toshiharu INAGAWA


  We developed a non-destructive evaluation system for tunnel concrete lining. The system is composed of three elements. The first element is tapping mechanism; the second element is a measuring technique of the sound of concrete; and the third element is an analysis algorithm of the sound wave. The tapping mechanism which we considered uses the steel ball suspended with several rubber string. The steel ball is pulled and released. The sound of concrete is effectively caught by a microphone with a special noise-proofing hood that is pressed against the lining. By the analysis of the sound wave using wavelet transform, we can approximately estimate several state parameters of lining concrete, such as the thickness and position of defects like cavities in and behind the lining.


* Full papers of RTRI Report are written in Japanese.

Copyright (c) 2001 Railway Technical Research Institute