2024 Volume 80 Issue 17 Article ID: 24-17201
Cavity collapse caused by internal erosion of backfilling sand has occurred frequently at the back sides of coastal structures such as seawalls and quaywalls worldwide. To prevent the internal erosion-induced damage, it is crucial to detect cavities under the pavement at an early stage. In this study, prototype-scale model experiments were conducted to investigate the effects of asphalt and concrete pavement types and thickness on the accuracy of cavity detection using a ground-penetrating radar (GPR). The results showed that the type and thickness of the pavement greatly affected the detectable depth of the cavity using the GPR. It was difficult to detect cavities when they were formed and developed deeper than 1 m below the pavement surface, depending on the type and thickness of the pavement. In addition, by comparing and verifying the obtained GPR signal patterns at a certain periodic interval under the pavement, it was possible to accurately detect and identify the depth of cavity development at an early stage, namely from 1.0 m or deeper below the pavement.
