PSI - Issue 44

Emanuele Renzi et al. / Procedia Structural Integrity 44 (2023) 737–744 Emanuele Renzi et al./ Structural Integrity Procedia 00 (2022) 000–000

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built before 2003 for which design documents are available for which design documents are available that give account of this assumption may also be considered to have been built according to anti-seismic design criteria». Like the static and foundational classification, in defining the bridge vulnerability, the actual state of conservation of the structure must be considered, to be assessed by visual inspections. The OI linked to the defectiveness definition better clarifies the concepts of "Defectiveness of the individual structural elements" and "Defectiveness of a span, of every element or of the substructure and of the entire work”. The combination of these parameters (static scheme, light and materials, design criteria and defectiveness level) provides the seismic vulnerability class of the bridge. The seismic exposure class is determined starting from the structural and foundational exposure class, considering factors such as the ADT (TGM in Italian), the average span light, the presence of road alternatives and the type of bypassed entity. To these must be added a further measure linked to the strategic nature of the work in the event of an emergency. The OI at § 4.3.4.1 explains «in the event of lack of different specific indications, the strategic nature of the work is evaluated with reference to the Decree of the Head of the Department of Civil Protection n. 3685 of 21 October 2003». The OI at § 4.3.5.2 reports: «if there are accurate assessments of the seismic conditions carried out in according to NTC or according to these Bridge Guidelines, from which the bridge is seismically adequate and which in any case consider the current state of conservation of the work and all the elements of degradation, the bridge is to be considered adequate from the point of view of seismic conditions, and the seismic AC is to be considered low» 6. Conclusions and future development The OI integrated in the text of the Bridge Guidelines enrich the original work by helping to limit the inevitable dispersions in interpretation by the operators that are called to evaluate the overall AC of a bridge, a viaduct, an overpass and in general a roadwork under the scope of guidelines. The new regulatory instrument, helps the road operators to critically analyze the genesis of the evaluation of the overall AC of the roadwork, both on the basis of the result obtained for the single risk, static-foundational, seismic, hydraulic, landslides, and on the basis of the critical issues that led to the individual assessments, hazard class, vulnerability classes, exposure class, planning the consequent operations, provided for by the Bridge Guidelines, precisely on the basis of the analysis of these critical issues. The Agency has developed an important aid for operators and will await the return of experience in the use of the OI to develop a second updated edition and a cloud-based platform that integrate the Bridge Guidelines and OI for the automatic calculation of the overall AC. References Bazzucchi, F., Restuccia, L., Ferro, G., 2018. Considerations over the Italian road bridge infrastructure safety after the polcevera viaduct collapse: Past errors and future perspectives. Frattura ed Integrita Strutturale 12, 400–421. https://doi.org/10.3221/IGF-ESIS.46.37 Bortot, F., Zonta, D., Zandonini, R., 2006. A bridge management strategy based on future reliability and semi-Markov deterioration models, in: Proceedings of the 3rd International ASRANet Colloquium, Glasgow, UK. pp. 10–12. Buratti, G., Celati, S., Cosentino, A., Gaudioso, D., Mazzatura, I., Morelli, F., Messina, V., Salvatore, W., 2022a. The Structural Risk Assessment of Existing Bridges in Tuscany (Italy) a Quick Survey-Based Method, in: Pellegrino, C., Faleschini, F., Zanini, M.A., Matos, J.C., Casas, J.R., Strauss, A. (Eds.), Proceedings of the 1st Conference of the European Association on Quality Control of Bridges and Structures, Lecture Notes in Civil Engineering. Springer International Publishing, Cham, pp. 845–855. https://doi.org/10.1007/978-3-030-91877-4_96 Buratti, G., Celati, S., Cosentino, A., Gaudioso, D., Mazzatura, I., Morelli, F., Salvatore, W., 2022b. The New Guidelines of Italian Ministry of Infrastructures for the Structural Risk Classification of Existing Bridges: Genesis, Examples of Application and Practical Considerations, in: Pellegrino, C., Faleschini, F., Zanini, M.A., Matos, J.C., Casas, J.R., Strauss, A. (Eds.), Proceedings of the 1st Conference of the European Association on Quality Control of Bridges and Structures, Lecture Notes in Civil Engineering. Springer International Publishing, Cham, pp. 835– 844. https://doi.org/10.1007/978-3-030-91877-4_95 Calvi, G., Moratti, M., O’Reilly, G., Scattarreggia, N., Monteiro, R., Malomo, D., Calvi, P., Pinho, R., 2018. Once upon a Time in Italy: The Tale of the Morandi Bridge. Structural Engineering International 29, 1–20. https://doi.org/10.1080/10168664.2018.1558033