PSI - Issue 84

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

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Fig. 3. A bridge serving a salt pond near Ferrara, Italy, which failed due to corrosion of tendons.

3. Methodology To assess the interactions between the bridge and the hydraulic infrastructure, data were collected through systematic field inspections. Based on the collected data, a Failure Modes and Effects Analysis (FMEA) was performed (Mikulak et al., 2017). This analysis enabled the identification of the principal failure modes and their associated effects on the hydraulic infrastructure, allowing the interdependencies between the two systems to be systematically evaluated. The analyzed infrastructure, located in lowland areas, has the regulation of water levels necessary for agricultural use as the main function. However, occasionally it also serves for flood disposal and drainage. In recent times, this second function is becoming increasingly important due to climate change and related extreme rainfall events. It is then evident that the loss of functionality of the infrastructure may have a significant territorial impact, and maintaining the relevant bridges operational is essential to ensure access to strategic flood regulation devices. Interdependence is therefore fundamental to hydraulic functionality. A clear example is provided by the assessment of hydraulic infrastructure performance following an earthquake. As proposed by Nale et al. (2025), following a seismic event, it is necessary to evaluate the operational functionality of hydraulic structures during the emergency phase (Fig. 4). Indeed, the definition of the damage class depends on the ability to inspect the infrastructure on-site and to perform the necessary operations to verify its actual functionality. In this context, it is essential that the bridge serving the hydraulic infrastructure remains safely passable, not only to accommodate potential vehicular traffic but also to allow direct on-site inspection of the hydraulic structure, particularly in cases where remote monitoring is absent or unavailable. Assessing the relevant failure modes and the interdependence between the bridge and the hydraulic infrastructure is essential for developing a valid and robust procedure, applicable not only during the emergency phase but also in the management phase. It also allows defining the necessary measures to restore functionality in the shortest possible time. 3.1. Data collection and inspection During the data collection and inspection phase, the main structural defects of the bridges were identified and classified according to their potential impact on the hydraulic infrastructure. Common issues include corrosion of reinforcement in concrete piers, abutments, and girders, as well as deterioration of post-tension RC decks, which can lead to cracking, loss of post-tension in tendons, and reduced load-bearing capacity. Masonry arches exhibit mortar degradation and element detachment, often exacerbated by seismic events. Movable bridge mechanisms may experience mechanical blockage due to debris accumulation or insufficient maintenance, limiting navigability and obstructing water flow. Foundations are susceptible to scour and settlement during flood events, potentially compromising bridge stability. The collapse of secondary elements, such as parapets and railings, or the accumulation of debris against the bridge, may cause partial channel obstruction, increasing upstream hydraulic risk. These observations form the basis for a risk-oriented assessment and highlight the interdependence between bridge structural conditions and hydraulic system performance. Figure 5 highlights typical structural issues identified in the inspections.