Detecting defects in or behind tunnel lining concrete using electromagnetic wave radar with change of antenna type and frequency domain

摘要

The presence of defects (including cavities et al.) in or behind tunnel lining of concrete is likely to result in collapse. One method of detecting such cavities by non-destructive means is radar. By the way, the cavity of small size and deep depth can't be detected easily by the present radar technology when it applies to civil structures. To overcome these problems and limitations, this study aims to propose and develop a fitting frequency of radar and analysis method for detecting cavities in or behind tunnel lining concrete. Study for a fitting frequency of radar and analysis method is based on the experiments with various types of cavities and change of radar frequencies. As the results, it is clarified that a proposed fitting frequency and analysis method has a possibility of detecting various types of cavitations in or behind tunnel lining concrete.