Geotechanical Characterization of the Levees of Tagliamento River (Italy): Insights and Implications for Levee Vulnerability

Recent flooding events in the Po Plain have once again highlighted the critical importance of river embankments in protecting against hydrogeological risk. The current characterization methodology relies on localized investigations (penetrometric tests and boreholes), combined with geophysical surveys. However, spatial variability and the presence of local heterogeneities of diverse origins can promote various forms of instability and, in the worst-case scenario, lead to breaching. Their analysis necessitates novel investigation methods and data analysis techniques.
This study presents the characterization of the lower Tagliamento River embankments, conducted through two investigation campaigns encompassing 120 CPTs (Cone Penetration Tests), 20 boreholes, and several ERT (Electrical Resistivity Tomography) surveys, covering a length of 40 km. Additionally, 15 CPTs were performed in closely spaced vertical profiles, at intervals of only 6 meters.
The results were analysed to assess the vertical and longitudinal spatial variability of specific soil characteristics at various scales, with the aim of enhancing the reliability of embankment safety evaluations.

Keywords: Embankments, Levee, Site investigation, Spatial variability, Closely spaced CPT.