Stay Cables help span the Paraná River
The new 60 km long road connection between the cities of Rosario in the Santa Fé province and Victoria in the Entre Ríos province has been under construction since 1998 to substantially facilitate inter regional traffic between Argentina, Uruguay and Brazil. The overall project consists of a series of dams with a combined total length of 48 km and several bridges.
The main bridge is a 608 m long stay cable structure over the Paraná River with two approach spans measuring 1.1 km and 2.4 km in length. The main span is 350 m long providing 50 m vertical clearance for shipping. The side spans are 120 m long.
The schedule posed several challenges to the project participants: the superstructure segments were built using the free cantilever method on both sides of the pylon. During concreting the form travellers were temporarily supported by the stay cables of the respective segment. After the concrete had cured, the load of the cables was transferred from the form traveler to the deck segment by corresponding manipulation of the deck anchorage.
Another technical challenge was the bracing of the pylon to the abutment pier during the free cantilevering on both sides. This was done using the stay cables of the end segment of the side span. Since there was no firm connection between the pylon and the abutment pier at that construction stage, the two 145 m long cables had to be pulled in using a 150 m long auxiliary tendon consisting of four bare strands.
The DYWIDAG DYNA Grip® stay cable system was used for this project. The tension elements consist of galvanized strands that are waxed and PE sheathed enclosed in a white HDPE duct. The strands are installed in DYNA Grip® anchorages designed for superior fatigue resistance. For the prestressing of the cables the DYWIDAG-CONTEN method in combination with large gradient jacks was used. A total of 720 tons of 0.62" strands were installed for the 31, 37, 55, 61, and 73 size cables.