Caratterizzazione geofisica di un tratto d'argine ricostruito in seguito a rotta.

The characterization and the monitoring of levee bodies is a common issue that affects both natural and man-made structures, given the increasing occurrence of stability problems. A possible approach to these questions is provided by integrated geophysical investigations, which are non-invasive, cost effective and easy-to-apply. In this work we present the Frassine river embankment case study (Padova, Italy), whose reconstruction took place after its collapse due to a flood in 2010. The rebuilt section of this levee is composed of a bouldering structure with a grouting diaphragm in the central part. Here we combined electrical resistivity tomography (ERT), multi-channel analysis of surface waves (MASW), ground penetrating radar (GPR), and self-potential (SP) in order to investigate inner heterogeneities, mechanical properties, moisture content, and water flows respectively. The results show evident heterogeneities in the structure, both in transverse and in longitudinal directions and, more in detail, the grouting diaphragm does not show the high resistivity values we expected from the initial longitudinal resistivity sections. This work, moreover, shows how important and useful the integrated application of different methods to investigate river embankments is and underlines the importance of acquiring data also in transverse direction.