Preliminary probabilistic assessment of the seismic response of link slab viaducts

Recent seismic events occurred in Central Italy drew the attention towards the resilience of the Italian road network, which is characterised by a significant number of old reinforced concrete bridges and viaducts. In this context, the fragility assessment of existing bridges is crucial, since their collapse or loss in functionality after earthquakes may lead to significant economic and social consequences. As a preliminary study oriented to characterizing the fragility level of the Italian bridge heritage, this work focuses on the real case study of the Chiaravalle viaduct, located in Central Italy, which may be representative of a widespread class of reinforced concrete bridges in Italy. The viaduct is a continuous multi-span bridge consisting of precast simply supported V-shaped beams connected by a continuous upper slab. A numerical model is developed in order to capture the failure mechanisms most likely to occur for this bridge typology subjected to seismic actions. A probabilistic assessment of the seismic response of the bridge is carried out by performing multiple stripe analysis (MSA), and a preliminary interpretation of the results is provided. Future studies will be aimed to the development of fragility curves, by accounting for all the relevant demand parameters and limit states.