Every year, numerous prestressed concrete (P/C) girder bridges are damaged by overheight vehicles. When this happens, bridge engineers are faced with numerous questions relative to the behavior and strength of the bridge. These questions must be answered so decisions can be made concerning traffic restrictions and future maintenance actions. Results of an investigation of damaged P/C bridge behavior and damaged P/C beam strength are briefly presented in this paper. In this project, two P/C bridges carrying I-680 near Beebeetown, Iowa were tested. The westbound bridge was accidentally damaged and tested in the damaged state and following replacement of the damaged beams. The eastbound bridge was not damaged and was used as a reference. Following testing of the bridges and removal of the damaged beams, one of the beams was tested in an "as-removed" condition while the other was strengthened with carbon fiber reinforced polymer (CFRP) longitudinal plates and external CFRP stirrups. Both beams were tested to failure. Additionally, a three beam laboratory P/C beam bridge model was tested. The model had a total length of 40 ft 4 in. (12.29 m) and a width of 18 ft (5.49 m). The bridge model was tested 180 times to study the effects of incremental damage and load placement on the behavior of a controlled specimen. Following testing of the model, two of the beams were removed, the first was tested in an undamaged condition, the other following intentional damage and CFRP repair. Both beams were tested to failure. An additional component of the work was the development of several analytical models of the damaged and repaired bridges. Both three-dimensional grillage (downstand grillage) and stiffened plate models were created. The models were calibrated using the experimental deflections recorded during both bridge tests. The analytical models were used to describe the live load distribution patterns in both the damaged and undamaged bridges. Significant redistribution of moment away from the damaged beams to the adjacent undamaged beams and curb/rail section was observed.


  • English

Media Info

  • Features: Figures; Photos; References;
  • Pagination: p. 109-114

Subject/Index Terms

Filing Info

  • Accession Number: 00793279
  • Record Type: Publication
  • ISBN: 0965231046
  • Files: TRIS
  • Created Date: May 23 2000 12:00AM