PSI - Issue 84

L. Fieno et al. / Procedia Structural Integrity 84 (2026) 1136–1143

1143

Fig. 8. 2025 Special Inspection Campaign – Expert Assessment Results A case of restrictive management measures applied to a post-tensioned box-girder viaduct during a special inspection is presented. The deterioration detected in the harmonic reinforcements necessitated limiting vehicle weight to 44 tons and closing the emergency lane to traffic. These measures ensured operational safety throughout the design and execution of the repair and strengthening works.

Fig. 9. Example of Management measure

7. Conclusions Special inspections allow for a more thorough and targeted assessment of the condition of structural elements. The high level of detail required in carrying out these activities, together with the use of specific diagnostic investigations on the most deteriorated portions, significantly contributes to increasing the level of knowledge of the structures. This aspect is particularly relevant for post tensioned prestressed concrete bridges, in which degradation phenomena or hidden defects may not be detectable through simple visual inspection. From the analyzed cases and the presented case studies, it emerges that apparently minor and difficult to detect deterioration may in fact conceal significant structural criticalities, highlighting the importance of the accuracy of inspection activities and of the correct interpretation of the obtained results and available documentation. Overall, the results confirm the central role of special inspections in the process of knowledge acquisition, safety assessment, and management of existing infrastructure, emphasizing how such activities may require the timely implementation of safety measures or the adoption of restrictive management actions, as a basis for the subsequent planning of interventions. References D.M. 17 gennaio 2018. Norme tecniche per le costruzioni (NTC 2018). Ministero delle Infrastrutture e dei Trasporti, Roma. Circolare 21 gennaio 2019 n. 7. Istruzioni per l'applicazione delle "Norme tecniche per le costruzioni" di cui al D.M. 17 gennaio 2018. Consiglio Superiore dei Lavori Pubblici, Ministero delle Infrastrutture e dei Trasporti, Roma. D.M. 17 dicembre 2020 n. 578. Linee guida per la classificazione e gestione del rischio, la valutazione della sicurezza ed il monitoraggio dei ponti esistenti. Ministero delle Infrastrutture e dei Trasporti, Roma. Istruzioni operative ANSFISA, 2022. Istruzioni operative per l'applicazione delle Linee guida ponti (adottate con Decreto del Presidente del Consiglio Superiore dei Lavori Pubblici 21 settembre 2022). Agenzia Nazionale per la Sicurezza delle Ferrovie e delle Infrastrutture Stradali e Autostradali, Roma.