Dynamic tests and modal identification of Corso Grosseto viaduct decks before the dismounting

This paper describes the dynamic test campaign carried out on four prestressed concrete decks being part of the viaduct of Corso Grosseto in Turin, before its demolition after a service life of 50 years. Subsequently, 25 beams, 4 box girders and 2 pier caps were collected from the tested decks to be deeply investigated within the frame of BRIDGE|50 research project. The purpose of the preliminary test campaign is to characterize the dynamic behavior of the decks in their service condition. Dynamic measurements were acquired on each deck by using different excitation sources. The collected data have been analyzed in order to extract the principal modal components and the outcomes have been compared to the analytical results given by a FE model. The results of the tests will be used to better investigate the effectiveness of the dynamic tests in the assessment of ageing infrastructures, to explore the effects of damages on single beams and its influence on the global response of this bridge typology