COMPARISON OF MEASURED AND COMPUTED STRESSES IN A STEEL CURVED GIRDER BRIDGE

Steel curved I-girder bridge systems may be more susceptible to instability during construction than bridges constructed of straight I-girders. The aim of this research was to study the behavior of the steel superstructure of a curved steel I-girder bridge system during all phases of construction and to ascertain whether the actual stresses in the bridge are represented well by linear elastic analysis software developed for this project and typical of that used for design. 60 vibrating wire strain gauges were applied to a 2-span, 4-girder bridge, and elevation measurements were taken by a surveyor's level. The resulting stresses and deflections were compared to computed results for the full construction sequence of the bridge as well as for live loading from up to 9 50-kip trucks. Analyses correlated well with field measurements, especially for primary flexural stresses. Stresses due to lateral bending and restraint of warping induced in the girders and stresses in the cross frames were more erratic but generally showed reasonable correlation. In addition, it is shown that, for the magnitude of live load applied to the bridge, analyses in which composite behavior is assumed in the negative moment region yield better correlation than analyses in which just the bare steel girders are used. It is concluded that the curved girder analysis software captures the general behavior well for these curved girder bridge systems at or below the service load level, and that the stresses in these bridges may be relatively low if their design is controlled mostly by stiffness.

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  • English

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  • Accession Number: 00797579
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 2 2000 12:00AM