PSI - Issue 84

Rosario Montuori et al. / Procedia Structural Integrity 84 (2026) 967–974

974

A further fundamental aspect for the overall evaluation is the estimation of the reliability and completeness of the data collected during the inspection phase. This aspect represents an additional difference with respect to the 2020 Guidelines, while at the same time constituting a fundamental requirement for non-concessionary Road Authorities. Indeed, within a context of limited resources, it is not always possible to fully inspect all the elements constituting a bridge structure. Constraints related to orography, the presence of dense vegetation, watercourses that cannot be crossed without special equipment, the need to pass through private properties, and similar issues often make a complete inspection of the structure impossible. It is therefore necessary, particularly during the first inspection, to quantify the portion of each structural element that can be inspected and to assess which actions are required in order to carry out a complete inspection. Information related to inspection reliability may be addressed through specific assignments that the administration can commission independently of routine inspections, with the aim of ensuring full accessibility to the structures to be inspected. At the same time, this information is extremely useful for improving the reliability of subsequent inspection campaigns. For this purpose, the Global Reliability Index (GRI) is introduced. This index, obtained as a weighted average of the Element Reliability Indices, quantifies the trustworthiness of the Damage Indices. It is defined as: = ∑ ∙ ∑ [%] (11) From its definition, it is clear that reliability is essentially related to the observable percentage. Consequently, a reliability value equal to 70 indicates that 70% of the bridge was inspectable, while the remaining 30% was not inspectable. No information is reported for the non-inspectable portion: what cannot be observed cannot be assessed. Therefore, all information related to defectiveness must refer exclusively to the inspectable portion of each element. The fundamental objective of subsequent inspections is to increase inspection reliability and, compatibly with the available resources, to progressively reach a reliability index equal to 100%. 4. Conclusions In the present work, a methodology for the inspection and vulnerability assessment of bridges has been briefly illustrated, which can represent a highly valuable tool for all non-concessionary Road Authorities, namely provinces, regions, and municipalities. Following the issuance of the 2020 Guidelines, these authorities have been faced with the need to address a problem that is excessively large and demanding with respect to the available human and economic resources. The proposed methodology includes a simplified version of the Defect Forms compared to those provided by the 2020 Guidelines and focuses exclusively on the evaluation of the most severely damaged structural element for each individual bridge structure. In this way, it is possible to establish rational and effective planning of rehabilitation interventions. This tool enables the administration to operate in a transparent manner, since, once the methodology to be adopted has been defined, the final outcome automatically determines which bridge structures will be the first to be subjected to intervention. Furthermore, the assessment of the reliability of the individual structural elements and of the entire bridge structure, namely the evaluation of the observable percentage of each element and of the structure as a whole, allows the administration to plan activities aimed at increasing inspection reliability in future campaigns, with the objective of ultimately reaching a reliability value equal to 100% for the entire bridge structure. References AA. VV. 2007 American Association of State Highway and Transportation Officials, Manual for Roadways and Bridges Mark H., Steven D.S., 2001, Highway Bridge Maintenance Planning and Scheduling - ISBN: 978-0-12-802069-2. Ryall, M.J. 2010 - “Bridge Management”, Butterworth-Heinemann, Oxford,-ISBN-13:978-0-7506-8511-5 AA. VV. Manuale – 2018, Edizione CIAS - Valutazione dello stato dei ponti – MIT, DM 578/2020, Linee guida per la classificazione e gestione del rischio, la valutazione della sicurezza ed il monitoraggio dei ponti esistenti Montepara, A., et al. 2019, Sviluppo di una nuova metodologia per la valutazione delle priorità di intervento di manutenzione di ponti e viadotti. 17° Convegno Nazionale della Società Italiana Infrastrutture Viarie. Valenzuela, S., Solminihac, H. De., Echaveguren, T., 2010. Proposal of an Integrated Index for Prioritization of Bridge Maintenance. 15:337–343 Braga et al. 2019 - Multi-level approach for the assessment of bridge and viaducts within road networks – XVIII Convegno ANIDIS 2019