Prestessed Bridge over the Caroni River, Venezuela

Abstract

This bridge consists of a. series of portal frames, of 96 m span each, making up a total length of about 500 m. The piles over the river have caused certain difficulties, and it became necessary to build a number cofferdams with sheetpiling, which became permanent formwork for the concrete foundations. The deck is a box section beam, of prestressed concrete. The most notable aspect of this structure is the constructive method. The total length of the deck was divided into 50 sections, each of them prefabricated at a nearby workshop. Each section was aligned along the deck axis: the deck already built serving as sliding ramp for each successive section. To carry out this difficult operation, neoprene was employed, which has a very low friction coefficient, on sliding over steel. To push the heavy table sections to their final position use has been made of hydraulic jacks. After these initial operations were completed, the groups of prestressed cables were correctly aligned: these cables had been provisionally stretched, during the process of putting the deck sections together. These groups of cables are attached to the inner surface of the side walls of the box sections of the deck.