Presidente Ibáñez Bridge: Chile’s longest suspension bridge
The 210 m long Presidente Ibáñez Bridge in the Aysén region of southern Chile is the country's longest suspension bridge and has been declared a national memorial. Completed in 1966, the bridge crosses the Aysén River and is a historic monument for the architectural style that was typical for public construction projects during the 1960s. The structure connects the region's largest harbour, Puerto Chacabuco and the regional capital of Coyhaique with the rest of the country, thus continuing to fulfil an important transportation function even today.
The Presidente Ibáñez Bridge was built on reinforced concrete foundations and features two 25 m high metal piers that support eight suspension cables per side. On both sides of the main support cables, 22 vertical hangers connect the main suspension cables to the bridge deck. These hangers support the stiffening girders and cross beams that carry the reinforced lightweight concrete deck slab.
In order to maintain the bridge, comprehensive repair measures were carried out a few years ago. Within the scope of the repair work, the corroded coating of the complete bridge was replaced, new guide rails were installed and large level differences were evened out on the deck at both ends of the bridge. Furthermore, the elastic confinement of the main cables was renewed, and the tar that had been used was replaced by polyurethane foam.
Within the scope of further reinforcement measures, DSI Chile was asked to reinforce four vertical hangers in the middle of the bridge deck. For this purpose, DSI supplied 16 Ø 32 mm DYWIDAG Post-Tensioning Bars that were installed at each of the hangers in question in a supporting structure that was additionally fixed to the bridge deck.
Four DYWIDAG Bar Tendons were arranged vertically around each of the hangers. This structure permits a reliable transfer of loads from the hangers to the DYWIDAG Bar Tendons. The DYWIDAG Bars were post-tensioned using four 110 MP jacks connected via a manifold to a central hydraulic pump ensuring an even distribution of pressure to all four jacks. In addition, DSI supplied 24 short Ø 32 mm DYWIDAG Bar Tendons that were horizontally installed into the new supporting structure and post-tensioned to 600 kN using a torque wrench.