Analysis of GPR wavefield characteristics of road cavities

This is the authors' abstract. We don't add key points for this paper.

Cavities are a prevalent and highly hazardous road disease that can cause collapse. Utilizing 3D GPR for road cavity detection can effectively mitigate such incidents. However, the propagation characteristics of electromagnetic waves in the underground 3D space are not fully understood, presenting a challenge in identifying road cavities. To clarify the wavefield characteristics of cavities, numerical simulation studies are essential to guide the interpretation of field data. Considering the higher computational cost of 3D simulations, it is common to employ 2D simulations in practical applications. Nonetheless, the rationality of this approach requires further discussion and evaluation. Therefore, this study conducted numerical simulation experiments based on both 2D and 3D cavity models and subsequently analyzed the results. We found that the results of the 3D simulations are more realistic, which is confirmed in the field data. But there is no denying that 2D simulations can significantly reduce computational costs and have advantages in highlighting the presence of cavities.