Numerical Investigations on the Collapse of the Morandi Bridge

Abstract

The collapse of a relevant portion of the Polcevera river viaduct, located in Genoa (Italy) and also known as Morandi Bridge, is herein object of a numerical investigation. The bridge was designed in the early 1960s by Riccardo Morandi, a well-known Italian engineer, and opened to the public in 1967. The collapsed part of the bridge essentially comprised an individual self-standing structure spanning 171 m and two simply-supported connecting Gerber beam systems, each spanning 36 m from the self-standing structure to the adjacent portions of the bridge. A previous investigation, by Calvi et al. (Calvi et al. in Struct Eng Int 29:198–217, 2019), indicated that the collapse of the bridge could have potentially been triggered by a sudden loss of effectiveness of one stay (e.g. due to the failure of either the deck-stay or the antenna-stay connections), which in turn would have induced a flexural–torsional-shear failure of the bridge deck. In the current work, therefore, the attention is turned into a more detailed study of the latter, through the employment of detailed Finite Element Analysis modelling, with a view to corroborate, or not, the results of the aforementioned previous study. As in the latter, the development of such model was based entirely on publicly available material that has so far been rendered online accessible. It is shown that should the support provided by one of the bridge stays be removed, the ensuing flexural–torsional-shear demand on the deck would be such that the latter would be led to the type of collapse observed in the field.