The “Filetto” Bridge on the Santerno River near Bologna (Italy): seismic retrofit and reinforcement design

The aim of the project work here presented is to investigate the seismic behavior of the Filetto Bridge (an historical prestressed r.c. bridge near Bologna in Italy) according to the rules of the new Italian Seismic Design Code. Preliminary analysis shows that the existing structure is not able to support the new seismic excitation mainly because the benefit of the post-stress is partially lost due to the traction stresses in the deck, and the present supporting devices cannot support the drifts between the pile and the deck. The results obtained from several static and dynamic analysis show the necessity of a reinforcement design; the fundamental solutions which provide the structure with the best performances are (i) the insertion of elastomeric isolators among the deck and the piers and (ii) the use of highly resistant carbon fiber strips in order to restore the loss of post-tension effect of the beams