CURVED STEEL BRIDGES

EXPERIENCE OF HOWARD, NEEDLES, TAMMEN, AND BERGENDOFF IN THE DESIGN AND CONSTRUCTION OF CURVED GIRDER BRIDGES IS DISCUSSED. IN ADDITION TO THEIR AESTHETIC VALUE, WHICH WAS THE PRINCIPAL CAUSE OF THEIR APPEARANCE IN THE 1960'S, CURVED GIRDER BRIDGES HAVE CERTAIN PRACTICAL ADVANTAGES: THEY PROVIDE CONCRETE DECK UNIFORMITY (THE OVERHANG FROM THE EDGE OF THE BEAM IS A CONSTANT VALUE), THUS SIMPLIFYING PLACEMENT OF THE REINFORCEMENT; THEY CAN BE USED IN URBAN AREAS TO OVERCOME GEOMETRIC RESTRICTIONS, AS ANY CURVATURE SATISFACTORY FOR TRAFFIC CAN BE MET BY THE GIRDER; LONGER CONTINUOUS SPANS CAN BE CONSTRUCTED, THUS REDUCING THE NUMBER OF EXPANSION JOINTS AND BEARINGS; AND THE CONCENTRIC CIRCLES OF THE CURVED GIRDERS GREATLY REDUCE ENGINEERING COMPUTATION OF OFFSETS AND CHORD LENGTHS. SOME OF THE PROBLEMS DISCUSSED IN THE LIGHT OF HNTB EXPERIENCE ARE CURVATURE WITH COMPOSITE ACTION, USE OF SHEAR CONNECTORS AND STIFFENERS, MEANS OF SHIPPING AND ERECTING, MEANS OF DECREASING THE TORSIONAL EFFECT FROM DEAD LOAD, COMPUTATION OF DEAD LOAD DEFLECTION, MEANS OF CURVING WELDED STEEL GIRDERS HORIZONTALLY, FABRICATION PROCEDURES, AND DEVELOPMENT OF A DESIGN METHOD UTILIZING THE CONTINUOUS BEAM COMPUTER PROGRAM. IN CONCLUSION IT IS CONTENDED THAT ALTHOUGH THERE ARE FABRICATION AND ERECTION PROBLEMS WITH CURVED GIRDERS, THEY ARE NOT COMPLEX, AND THAT ENGINEERING ANALYSIS OF CURVED GIRDER BRIDGES DOES NOT NEED TO BE EXCESSIVELY COMPLICATED.

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Filing Info

  • Accession Number: 00209518
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 20 1971 12:00AM