PSI - Issue 62
Alessandro Lipari et al. / Procedia Structural Integrity 62 (2024) 24–31 Author name / Structural Integrity Procedia 00 (2019) 000 – 000
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Table 3. Decision matrix (taken from Highways England (2020)).
3. Application to case studies The procedures presented above are applied to two bridges belonging to Italian national roads and located in the Calabria region. Both decks have their main components in prestressed concrete and feature comparable span lengths. 3.1. Case studies Bridge I is a four- span structure (maximum span 25 m), constructed in the early ‘70s and located in a mountain area. The structural scheme is made of post-tensioned PSC slabs supported on half-joints over the pier heads (Fig. 2a). The half-joints are critical elements and are not inspectable (Fig. 2b). There are clear signs of water leakage through the half-joints and corroded reinforcement on the soffit; therefore, according to the Italian guidelines, its level of deterioration is high, while according to the UK guidelines its conditions are poor. The supported route features a single carriageway with two lanes and a low level of daily traffic.
Fig. 2. Bridge I: (a) pier; (b) soffit at half-joint.
Bridge II is a seven- span structure (maximum span 32 m), constructed in the early ‘90s and located in an urban area. The structural scheme is made of pre-tensioned PSC girders with RC slab and diaphragms simply-supported over the pier caps (Fig. 3a). Defects are generally minor, with some limited areas of spalled concrete (Fig. 3b); therefore, according to the Italian guidelines, its level of deterioration is medium, whereas according to the UK guidelines its conditions are fair. The supported route features a single carriageway with three lanes. Traffic data has not been provided by the road manager; as such, a conservative assumption of high ADT and medium ADTT was made based on data available about similar routes in the same geographical area. The input parameters for both structures are reported in Table 1 and Table 2. Note also that, for both bridges, the design code, the presence of alternative routes, the transport of dangerous goods (Italian guidelines) and the applicable scenario (UK guidelines) had to be assumed due to lack of suitable data.
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