Launching of the Reno Bridge on the A1 Highway, Italy

Abstract

The new Reno Bridge, located at the foot of the Appennine chain near Bologna, belongs to the wide plan of modernisation provided for the improvement of the A1 Milan–Naples highway, called Variante di Valico.The bridge is a curved continuous prestressed concrete box girder 572,75 m long, supported by reinforced concrete vertical piers for the first six spans of 45 m and by two special framed Vshaped piers, which are rigidly connected to the deck, for the remaining “long span” zone (90 + 135 + 90 m). One of the peculiar aspects of the design is the construction process. Because of a very stringent working schedule, it was decided to plan for an incrementally launched structure, realised through the longitudinal launch of 45 m long segments. The special piers of the long span zone are formed by a concrete core encased in steel shells having the double function of formwork during casting, and reinforcement along the service life of the element. The inclined elements of the special piers, which are provisionally supported by auxiliary piers during launching, are rigidly connected to the deck once the structure has reached its final position. Figure 1 shows the new structure just before the opening of the south carriageway; on the left side the old alignment, no longer used, can be seen.