PSI - Issue 62

Carla Assunta Trifarò et al. / Procedia Structural Integrity 62 (2024) 57–64 C.A. Trifarò et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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2.2. Characterization of the sample A characterization of the sample is provided in Fig. 1. In particular, in the figure, data referred to type of structure, age of construction, material of the deck, static scheme, number of spans and total length of the analyzed structures are shown. As can be observed, the largest portion of the analyzed structures consists of bridges and viaducts (64%), thus the highway generally overpasses natural obstacles (i.e., rivers or orographic discontinuities). As for the age of construction, about 70% of the structures were realized before 1980, and in particular between 1970 and 1979 (about 50%). Almost the totality of structures is in reinforced concrete (r.c.) or prestressed reinforced concrete (p.c.). In this regard, it must be mentioned that two of the analyzed structures have been recently subjected to a demolition and reconstruction intervention and thus they have not been included in this sample characterization. As far as the static scheme of the considered structures is concerned, a significant prevalence (about 60%) of simply supported decks was observed. On the other hand, the data related to the number of spans and total length are quite heterogeneous. In particular, a slight prevalence of single-span and two- or three-span manufacts have been identified in the sample (about 50%). As for total length, it must be highlighted the presence of significantly long bridges, with a total longitudinal extension higher than 1 kilometer.

Fig. 1. Sample characterization: (a) type of structure, (b) age of construction, (c) deck material, (d) static scheme, (e) number of spans and (f) total length.

2.3. Attention classes For almost the entire stock, the 2 nd level of the procedure of the Italian Guidelines was applied. In particular, according to this methodology, data referred to exposure, vulnerability and hazard of each structure and concerning the different sources of risk (structural/foundational, seismic, hydraulic and landslide) are combined in order to obtain an estimation of the so- called “attention class”. The results related to the structural/foundational and seismic attention classes are shown in Fig. 2.