PSI - Issue 84

Marco Nale et al. / Procedia Structural Integrity 84 (2026) 329–336

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2. Case study: the bridges of the hydraulic network in Ferrara The bridges analyzed in this study are part of various hydraulic infrastructures, which in turn constitute an integral component of the hydraulic network in the Ferrara area (Table 1). The study area is bounded to the north by the Po River, to the east by the Adriatic Sea, to the south by the Reno River, and to the west by the Cavo Napoleonico (Fig. 1). This territorial framework allows for the analysis of a complex hydraulic system, characterized by strong interconnections between regulatory structures, reclamation channels, and crossing infrastructure. In particular, the Cavo Napoleonico plays a strategic role in the flood attenuation in the Reno River and in the water supply for the eastern territory. This infrastructure, together with its associated hydraulic node, is crucial during flood events, contributing to the reduction of hydraulic risk downstream over a large portion of the territory. Similarly, the hydraulic network within the study area is of fundamental importance for flood protection in the Ferrara flat plain that partially lies below sea level, ensuring proper discharge of flows and water level regulation. Within the analyzed area, there is significant variability in both seismic and hydraulic hazards. Coastal areas exhibit lower seismic hazard and generally lower hydraulic risk compared to inland zones. Most of the bridges in these areas were built before 1980 and show high heterogeneity in terms of structural type, materials, and condition. This study analyzed different types of bridges representative of the local infrastructure stock (Fig. 2): masonry arch bridges, such as the Gandazzolo bridge; steel lift bridges, such as the Valpagliaro bridge; and Reinforced Concrete (RC) bridges, such as those associated with the Opera Reno and the Opera a Po. This typological diversity allows investigation of different vulnerability mechanisms and possible failure modes, as well as the assessment of their impact on the overall functionality of hydraulic infrastructures in a multi-hazard context. Among the RC bridges, the Pontelagoscuro bridge, associated with a navigation lock on the Boicelli Canal, is currently in good condition. In contrast, the bridge associated with the Opera a Po shows a high degree of degradation affecting piers, abutments, and beams. Widespread cover deterioration and reinforcement corrosion compromise both the load-bearing capacity and durability of the structure, increasing the vulnerability of the infrastructure to both hydraulic and seismic events. Marked degradation phenomena are particularly observed in coastal areas, where the aggressive environment promotes corrosion processes. These phenomena are especially critical for bridges with reinforced and post-tensioned concrete beams, whose performance can be significantly affected by the chloride-induced corrosion of reinforced bars and post-tensioned tendons (Minghini et al. 2024), thereby impacting the durability and load-bearing capacity of bridge decks (Fig. 3).

Fig. 1. Hydraulic infrastructure (red spots) and related bridges in Ferrara territory.