PSI - Issue 84

Angelo Masi et al. / Procedia Structural Integrity 84 (2026) 321–328

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ReLUIS Consortium on behalf of the High Council of Public Work as part of the Ministry of Infrastructure (MIT). Data were collected by 24 Research Units (URs) from 18 Italian universities, which jointly contributed inspection results for a large portfolio of bridges managed by national and local road authorities. The database (Masi et al., 2025) was populated using a standardized Excel-based form distributed to all participating URs, ensuring consistency and comparability of the collected information (Fig. 3). The database integrates data derived from Level 0 forms, available design documentation, and Level 1 inspection forms. General information includes bridge identification, geographical location, construction period, and inspection date. Additional fields describe bearing geometry, material, restraining function (fixed or movable), operating principle, and design standards, together with a concise textual description of the device. For each bearing, up to six concurrent defects can be recorded, along with their associated extent and intensity values as prescribed by LG2020.

Fig. 3. Data included in the database

The preliminary database analysis allowed to recognize that the current structure of the Level 1 form presents some limitations. In particular, it does not explicitly require the identification of the bearing typology through a dedicated field. As a result, bearing type often has to be inferred indirectly from the reported defect category, which may lead to ambiguity and loss of information continuity between successive inspections. Yet, the form does not include a dedicated section specifically addressing steel–PTFE bearings and their typical defects, such as deformation / wear of steel and PTFE sliding surfaces or bolt loosening. In addition, a defect field related to the deterioration of reinforced concrete bearing supports is missing, despite this type of damage being frequently reported by inspectors in the notes section (Masi et al., 2025). These observations suggest the need for a revision of the bearings form in an updated edition of the LG2020. 3. Database analysis The developed database includes approximately 12,000 bearing devices installed on 255 bridges distributed across the Italian territory (Masi et al., 2025). Although some regions are not represented, the analysed bridge stock can be considered sufficiently widespread at the national scale, with only five regions lacking data (Masi et al., 2025), thus providing a representative overview of bearing typologies adopted on major highways and state roads (Fig. 4). From a typological perspective, elastomeric bearings clearly dominate the dataset, accounting for slightly more than half of the inspected devices. Pot bearings and steel–PTFE sliding bearings represent comparable shares, each close to 15–17%, while traditional steel bearings account for a smaller but still significant portion. Other bearing types, including seismic isolation devices, are only marginally represented, and a limited fraction of bearings could not be classified due to insufficient information. This distribution reflects both historical design practices and the progressive evolution of bearing technology over time, with elastomeric pads being extensively adopted from the 1960s onwards, and pot and steel–PTFE bearings becoming more common in bridges constructed after 1980 (Masi et al., 2025).