PSI - Issue 78

Andrea Pozè Falet et al. / Procedia Structural Integrity 78 (2026) 325–332

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(b) (d) Fig. 1. (a) Plan view, from Google Earth, of the Strambino Bridge (45°23'35"N 7°55'23"E). (b) View from the upstream West-side corner, with Pier P4 in the foreground; (c) Pier P2 after retrofitting (current conditions); (d) possible visual signs of scouring at Pier P3 between C3 and C4 (February 7 th , 2024). Notably, the infrastructure is located in an area strongly subject to flood hazard (see Figure 2). A nearby railway bridge on the Chiusella stream collapsed due to hydraulic causes during the October 13-16, 2000, flood event in Piedmont (D’Angelo et al., 2025) . Thus, hydrogeological phenomena can be considered as the prior threat to the case study. Conversely, the area is characterised by a low seismic activity (Figure 3), with an expected PGA of 0.041 g, considering the 50% percentile with 10% annual exceedance probability and return period Tr=50 years. (c)

Fig. 2. Flood Hazard map of the area surrounding the target bridge; retrieved from https://idrogeo.isprambiente.it/app/pir.

Fig. 3. Seismic site hazard; retrieved from hhttps://esse1-gis.mi.ingv.it/.