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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1. Introduction The orographic conformation of the Italian peninsula makes it one of the European and world territories with a larger density of road infrastructures. The Italian infrastructural heritage, with particular reference to road bridges, is characterized by non-negligible age and vulnerability (De Matteis et al., 2022a). Such a condition denotes a quite critical national scenario (De Matteis et al., 2023): many in- service road bridges were realized between ’60 s and ’80 s of the last century in reinforced concrete and many of them are inadequate to deal with the new traffic loads (Bencivenga et al., 2022). The problem related to the handling of such a wide infrastructural asset assumed in the last year a significant importance in the scientific community. In the past, many Italian road operators carried out inspections of bridges according to fixed deadlines indicated in ministerial circular no. 6736/61A1 (MLP, 1967) Worldwide Bridge Management System (BMS) research began in the USA in 1990s (Hudson et al.,1987) and in different European countries (Kähkönen et al., 1990, Marshall et al. 1990, Sorensen, 1990, Ingvarsson, 1992). In the following years, there has been a progressive evolution: in 2014, worldwide, there were 25 BMS used by 18 countries (Adei et al.,2010, Mirazei et al.,2012, Mirazei et al.,2014). Given the scale of the problem, indeed, insiders are recently moving toward the adoption of large-scale approaches based on multi-level procedures, which are preparatory for performing analyses at the level of the single structure. Such a tendency found at legislative level the issuing of the ministerial “ Bridge Guidelines ” for the correct handle of existing bridges (CSLLPP, 2020, CSLLPP, 2022). In this document, a multi-level holistic (i.e., including structural, seismic, hydraulic and landslide risks) approach is proposed (Santarsiero et al., 2021, Buratti et al., 2022a). This multilevel approach differs from other previous BMSs developed by local authorities in Italy, (Bortot et al., 2006, Zonta et al., 2007, Yue, 2013, Fattorini et al., 2023), thus, all management bodies are aligning their own handling procedures previously developed to the one described in this document. The importance of these Guidelines is further underlined in the research (Zizi et al. 2022, Cutrone et al., 2023), furthermore, several researchers have demonstrated the applicability of the Guidelines through selected case studies (De Matteis et al. 2022b, Di Sano et al.,2023, Buratti et al., 2022b) and the possibility of developing BMS software (Baratono et al., 2022, Manarin et al., 2022, Capogna et al., 2023, Viti et al., 2024, Natali et al., 2023a). In this national scenario, the National Agency for the Safety of Railway, Road and Highway Infrastructures (i.e., ANSFISA), as part of its regulatory autonomy, has developed Operating instructions for Bridge Guidelines (ANSFISA, 2022, Renzi et al., 2023, Natali et al., 2023b). Recently, this national body (i.e., August 2022) was involved in checking the safety conditions of one of the most important Italian highways (A24 and A25), which allows for connecting the west (i.e., Rome) and east coasts of the peninsula by crossing the central Apennine ridge. Within this activity, data referred to the structural conditions of infrastructures (i.e., bridges, viaducts, overpasses, and underpasses) having a total length higher than 6 meters were acquired. In this paper, these data are reported and elaborated with the aim to provide a clear picture of the situation that can be considered representative of other Italian highway networks, as well as to propose statistical approach for a smart prioritization (Meoni et al., 2023) and technical triage (Grimaz et al, 2024a,b) of the inspection activities. 2. The case study 2.1. Description of the highways The highways under investigation are the A24 (Rome – Teramo) and A25 (Torano – Pescara), which cross the Lazio and Abruzzo regions. The A25 highway branches off from the A24 at the junction of Torano and continues its route towards Chieti-Pescara, for a length of 114.90 km until the connection with the Adriatic A14 highway. The total length of this highway network amounts to about 280 km, of which about 20% consists of bridges. For the purposes of the present study, a total of 549 structures were considered.