Ground-penetrating radar for the structural evaluation of masonry bridges: Results and interpretational tools

Ground-penetrating radar (GPR) has shown good potential in providing valuable information for the evaluation of masonry structures. We used GPR to survey several stone arch bridges located in the Galician territory in Spain. The results revealed previously unknown geometrical data and hidden characteristics of the interiors of the bridges, including the presence of internal voids, ancient arches, and restorations. However, many factors can adversely affect a GPR survey, such as ringing noise and signal attenuation. These factors can make data interpretation complex. To assist in the interpretation, we employed numerical modelling because it can play a very important role in extracting valid and useful information from GPR data sets. The expected electromagnetic wave response can be simulated through the use of modelling tools. The obtained information can be useful for engineers, as it provides better structural knowledge of the bridge.

▸ A GPR survey methodology to assess stone masonry arch bridges is presented. ▸ The GPR results revealed unknown construction details and modifications over time. ▸ More realistic FDTD modelling was used to assess in the radar data interpretation. ▸ This work provided promising information to make decisions about stability.