New Bridge over the Tagliamento River – Extension of the Autostrada A4
Reliability and speed: the result of knowledge and organization
The bridge over the Tagliamento river consists of two decks (one in each direction) each of which has a width of 20.30 m. The work consists of two viaducts side by side, each with a 1,520 m long carriageway consisting of 19 spans on 20 piers, with a typical span of 81.6 m. The deck has a typical height of 3.20 m with an increase near the piers up to a maximum height of 4.00 m. The type of prestress used is that mixed with internal and external cables. The assembly was carried out in balanced overhangs. The final static layout of the decks is therefore a continuous beam divided by expansion joints. The lengths of the segments, which have a maximum weight of 110 tons, have variable values: 1.60 m for pile segments, 2.67 m for variable section segments and 2.85 m for constant section segments.
The segments were made in a 33,000 m2 prefabrication plant, built specifically for the work and located near the final installation area.
The transport of the segments from the prefabrication area to the installation area took place with rubber trolleys while the assembly was carried out with a specially made launching equipment.
The great level of organization and control, in addition to the high quality of the prefabrication systems, has allowed the production of segments with manufacturing tolerances of +/- 2 mm and a very fast assembly, greatly reducing the time initially foreseen.