DETERMINING BRIDGE RESPONSES TO OVERWEIGHT LOADS

The Wyoming Department of Transportation (WYDOT) Office of Overweight Loads issues overload permits to motor carriers based on the results of conventional structural analysis of bridges along the anticipated permit route. This study was initiated to determine if current analytical methods accurately represent the actual live-load response of common bridge types, or if the results are over- or under-conservative in predicting maximum stresses. Field test procedures consisted of performing diagnostic load tests on each structure type as it was subjected to both a standard vehicle load and then an overload/permit vehicle. Finite element models were developed and an analysis performed with the same loads as those applied in the field. Comparisons between the measured strains and the analytical strains were made, and each model systematically modified until comparisons were in good agreement. The three bridge types used in the study are: Reinforced Concrete (R/C) Slab Bridge; R/C T-Beam Bridge; and Slab/Steel Girder Bridge. The results demonstrated that the concrete slab bridge rated significantly higher than conventional analysis dictated. The actual load capacity of the steel bridge was also greater than conventional analysis predicted. While the capacity of the concrete t-beam was not as high as anticipated, in no instance were the actual capacities determined to be lower than conventional analysis indicated.

• Record URL:
  https://ntlrepository.blob.core.windows.net/lib/20000/20700/20784/PB98148976.pdf
• 
• Corporate Authors:

  Bridge Diagnostics, Incorporated

  5398 Manhattan Circle #100
  Boulder, CO  United States  80303-4239

  Wyoming Department of Transportation

  5300 Bishop Boulevard
  Cheyenne, WY  United States  82009-3340

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Schultz, J L
  • Commander, B C
  • Goble, G G
• Publication Date: 1998-3

Language

• English

Media Info

• Pagination: 103 p.

Subject/Index Terms

• TRT Terms: Bridges; Field tests; Finite element method; Girder bridges; Highway capacity; Live loads; Load tests; Oversize loads; Permits; Reinforced concrete bridges; Strain (Mechanics); Stresses; Structural analysis; T beams
• Uncontrolled Terms: Bridge capacity; Overloads
• Old TRIS Terms: Strains
• Subject Areas: Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00753812
• Record Type: Publication
• Source Agency: Wyoming Department of Transportation
• Report/Paper Numbers: FHWA-WY-98/01F,, RS08(197), Job No. R1H6,, Final Report
• Contract Numbers: 49565
• Files: NTL, TRIS, USDOT, STATEDOT
• Created Date: Sep 10 1998 12:00AM