Electrical Resistivity and Seismic Refraction Tomography to Detect Buried Cavities

Cavities located in the near surface represent a major hazard especially in sites located in highly urbanized town centers. For this reason, the location, the determination of size and shape of the cavity and the knowledge of the elastic properties of the overlying subsoil are necessary to evaluate the risk of subsidence and to plan the intervention for safety restoration. In this study, electrical resistivity tomography and seismic refraction tomography were performed with the twofold purpose of detecting the cavities and of optimizing an experimental procedure to better identify and locate them. These methods were tested on both synthetic and real data and the integrated geophysical approach has proven successful to detect single cavities together with their physical and geometrical characteristics.