Reflection Wave Property of Electromagnetic Radar according to Change of Depth and Thickness of Voids under Concrete Tunnel Lining

콘크리트 터널 라이닝 배면공동의 깊이 및 두께변화에 따른 전자파 레이더의 반사파 특성

This study aims to detect only voids and estimate the cross-sectional size and thickness of voids using radar. A new method based on radar image processing is carried out with various void sizes and depths. The regression relationship between void size which has different depth and the amplitude characteristics of the radar return is considered in a new method of this research. For the purpose of examining; this regression relationship, experiments with change of void depth, surface area and thickness were carried out. Finally, the threshold value for image processing which aims to represent only voids to be fitted size (width) can be obtained. As the results, a proposed method in this study has a possibility of detecting only voids and estimating void size and thickness with good accuracy.