PSI - Issue 84

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

327

sources, which are essential for inspecting structural components located in poorly lit or shadowed environments such as, for instance, near Gerber saddles (Santarsiero & Picciano 2024). Bridge bearings, in particular, are often positioned beneath the deck, close to abutments or piers, and partially hidden by surrounding structural elements. In such conditions, insufficient illumination significantly reduces image contrast and visibility, exacerbating the effects of limited resolution. As a result, defects affecting bearing devices may be underestimated, misclassified, or entirely overlooked when images are acquired using inadequate equipment. This issue underscores the need for minimum requirements on both imaging devices and acquisition conditions, including resolution and lighting, to ensure consistent and reliable visual inspection data. 5. Conclusions This study presented some of the results of an analysis of the large-scale bridge bearing inspection database developed within the experimental national application of the Italian Guidelines LG2020. Based on approximately 12,000 bearing records from 255 bridges, the work represents the most extensive systematic dataset on bearing typologies and defects currently available in Italy. While the database provides valuable insights into the distribution and condition of bearing devices, it also highlights significant limitations in current inspection practices. From a typological perspective, elastomeric bearings clearly dominate the inspected stock, followed by pot and steel–PTFE devices, reflecting historical design trends and technological evolution. Defect occurrence shows a strong dependence on bearing typology and age: elastomeric and traditional steel bearings exhibit higher degradation levels, mainly related to ageing, debris accumulation, and corrosion, whereas pot and steel–PTFE bearings generally display better conditions, with a higher proportion of defect-free devices. These findings confirm the need for typology-aware interpretation of inspection results. At the same time, the analysis exposes critical weaknesses in the inspection framework. The absence of dedicated fields for bearing typology description in Level 1 forms forces inspectors to infer key information from defect codes, increasing the risk of misclassification and reducing data consistency across inspections. This limitation directly affects the reliability of degradation assessment and long-term condition tracking. Additional challenges arise from the strong heterogeneity of photographic devices used during inspections and the wide variability in image resolution and illumination conditions. The frequent use of smartphones and tablets, often lacking adequate lighting, is particularly problematic for bearing devices, which are typically located in shadowed and confined areas. These issues may lead to underestimation or omission of defects. Overall, the results underline that improving inspection quality and data standardization is as critical as technological innovation. Revising inspection forms, refining defect taxonomies, and defining minimum requirements for image acquisition are essential steps to enhance data reliability and to enable future AI-assisted inspection tools for bridge bearing assessment. Acknowledgements This research was funded by the High Council of Public Works (CSLLPP) and was carried out as part of the activities envisaged by the agreement between CSLLPP and the ReLUIS Consortium implementing Ministerial Decree 578/2020 and Ministerial Decree 204/2022. The contents of this paper represent the authors’ ideas and do not necessarily correspond to the official opinion and policies of CSLLPP. References Bazzucchi, F., Restuccia, L., & Ferro, G. A. (2018). Considerations over the Italian road bridge infrastructure safety after the Polcevera viaduct collapse: Past errors and future perspectives. Frattura ed Integrità Strutturale, 46, 400–421. https://doi.org/10.3221/IGFESIS.46.37 Brighenti, F., Caspani, V. F., Costa, G., Giordano, P. F., Limongelli, M. P., & Zonta, D. (2024). Bridge management systems: A review on current practice in a digitizing world. Engineering Structures, 321, 118971. https://doi.org/10.1016/j.engstruct.2024.118971 Cosenza, E., & Losanno, D. (2021). Assessment of existing reinforced-concrete bridges under road-traffic loads according to the new Italian guidelines. Structural Concrete, 22(5), 2868–2881.