Historical reinforced concrete arch bridges of Songavazzo and Brivio (Italy): Dynamic identification and seismic vulnerability assessment

The problem of seismic safety assessment is discussed with reference to the case of an historical reinforced concrete bridge; specifically, a bridge located in Songavazzo, Italy across the Valeggia river, completed in 1911. Experimental testing has been performed, providing all the required information for the identification of the dynamic behaviour. Seismic vulnerability has been evaluated with both response spectrum modal analyses and nonlinear static (push-over) analyses as well. The bridge response is compared to the one obtained for a similar bridge yet reflecting a different structural scheme. Structural analyses have allowed to highlight different structural concepts while, on the other hand, they show the complementary nature of the two bridges. In both cases, reinforced concrete arches are mainly subjected to axial loads and provide the main structural system.