CONSTRUCTION METHOD FOR BRIDGE OR OVERPASS Russian patent published in 2005 - IPC

FIELD: road building, particularly road constriction in urban territories.

SUBSTANCE: method involves erecting piers; building at least one longitudinally solid span structure of reinforced concrete beams forming at least one branch in transversal cross-section. The beams are created in sections on jig of cast-in-place or composite reinforced concrete by means of concreting thereof in knock-down forms. The beams are reinforced with non-prestressed and prestressed reinforcement and beam sections are moved repeatedly in linear direction to design position with the use of launching nose. Prestressed reinforcement is arranged in bundles in closed channels. Each bundle is formed of wires and/or rods and/or bands of high-strength material, particularly of metal and/or metal-filled plastic or of high-strength carbonic or polymeric threads. Some channels are linear, another ones are curvilinear or polygonal and include convex and concave areas located mainly in vertical section. Convex and concave areas correspond or are proportional to bending moment profile. Working reinforcement arranged in linear channels is prestressed within each section before its displacement from jig. Reinforcement located in curvilinear or polygonal channels is pulled or drawn into channels after span structure or span structure branch movement in design position. Above reinforcement is prestressed after moving all sections forming span structure or part or branch thereof in design position. Ratio between cross-section areas and/or load-bearing capacity values of reinforcement prestressed in sections and reinforcement stressed after span structure or part or branch thereof movement in design position is (0.5 - 0.95):(0.5 - 0.05).

EFFECT: reduced material consumption, labor and power inputs, decreased erection time, increased erection safety and reliability of erected structure.

21 cl, 2 ex