Assessment procedure and rehabilitation criteria for the riveted railway Adige bridge

Traffic patterns increasing and the degradation of existing railway steel bridges has lead to the need of an assessment of their remaining fatigue life, and deciding whether to retrofit or supply structure replacement. This paper deals with the structural assessment of an actual case study, the Adige Bridge, which connects the Rovigo and Padua provinces in northern Italy. The bridge has been in service since 1886 and the overall length is about 161m through three spans. As a reference the innovative procedures to estimate the remaining fatigue life of bridges outlined in the JRC-ECCS document Assessment of Existing Steel Structures: Recommendations for Estimation of Remaining Fatigue Life, has been applied for the case study, together with other codes and technical instructions. Stress data, obtained by a 3D finite element model, were used to estimate the remaining fatigue life. Assessment results, obtained by considering different traffic estimations, point out that most of the identified critical details have an infinite remaining safe life, but at the same time some members appear critical. Appropriate retrofitting criteria are proposed to support the designer in common damage situations.