PSI - Issue 84

Michele D’Amato et al. / Procedia Structural Integrity 84 (2026) 536–543

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bridges. Level 1 is addressed to in-situ inspections. From a structural point of view, inspections are aimed at carrying out geometric surveys, but above all detecting the visual deterioration present on the bridge, hypothesizing its causes. Estimating the level of deterioration is essential for assessing the structural/seismic vulnerability of the bridge. The purposes of hydraulic inspections are to assess the stream characteristics, the relation between river and bridge, the type of foundation and the potential for scour (erosion). Finally, Level 2 is aimed at assessing the Risk Class, named Class of Attention (CoA), of Structural/Seismic, Landslides and Hydraulic Risks, and of the combination of them (Overall CoA). The possible resulting CoAs are: Low (L), Medium-Low (ML), Medium (M), Medium-High (MH) or High (H). a b c

Fig. 2. Abutment (a) and pier and foundations (b, c) scour: (a) due to incorrect rainwater drainage; (b) and (c) due to the river flow interaction. The present study is conducted to particularly analyze and assess the causes of erosion and scour processes affecting river crossing bridges distributed on the provincial road network of Matera. As reported in ( Fig. 2 ), the water flow has in some cases caused bridge foundation scour, requiring further assessment of this phenomenon. One may note that in Italian Guideline methodology pier or abutment foundations scour is defined as critical condition, triggering directly High Structural vulnerability class, High Structural CoA and High Overall CoA as well. 3.1. Database construction Based on field inspections carried out on Matera Province road network bridges in accordance with the Italian Guidelines (MIT, 2020), a database was developed containing geometrical, typological, material, morphological, hydraulic and the resulting CoAs. The surveyed bridges were classified according to their Hydraulic Hazard Class (Level 2, Hydraulic CoA - MIT, 2020). From the overall sample of 247 structures, a sub-sample of 95 is considered in this study, which are predominantly located along the secondary river network and have a Hydraulic Hazard Class ranging from H to ML. The construction materials involved (Fig. 3) in this sub-sample are: Reinforced Concrete ( RC =66.3%, 63 bridges) and Masonry ( M =28.4%, 27 bridges), with a low percentage of Cohesive Conglomerate ( CC =5.3%, 5 bridges). a b c

Fig. 3. Example of bridge piers in: a) RC; b) M; c) CC; d) pier material distribution within the three Matera Province Areas.