Seismic behaviour of simply supported reinforced concrete bridges with corroded piers

Corrosion is responsible for seismic performance degradation of reinforced concrete structures such as buildings and bridges. These latter suffer from chloride-induced corrosion due to de-icing salts used in winter times. When this problem affects the critical sections of bridges’ piers, the seismic capacity in terms of ductility and strength is highly affected. This paper aims to investigate the effect of steel corrosion damage in reinforced concrete bridges’ piers. To this end, a case study bridge (built in the 1970s and located in southern Italy) provided with hollow square section piers and simply supported steel and concrete decks, is analysed. Numerical simulations based on the incremental dynamic analysis approach are performed in order to evaluate the global bridge seismic behaviour. In fact, through the construction of the fragility curves of piers regarding different limit states, both in the as-built condition and in degraded ones, it is possible to determine and compare the seismic behaviour as a function of the corrosion extent.