Live-Load Testing and Finite-Element Modeling of a Fracture Critical Bridge

The Utah Transportation Center, in conjunction with the Center for Advanced Infrastructure and Transportation (CAIT) at Rutgers, sponsored a study that investigated the distribution factors and load ratings of a continuous, steel I-girder bridge. The SH-52 Bridge over the Snake River is located on the Idaho-Oregon border near Payette, Idaho. The bridge was built in the 1950’s and presently supports two lanes of traffic. A finite-element model of the bridge was calibrated with the results from a live-load test. For the live-load test, the bridge was instrumented at nine longitudinal cross section locations with 62 strain gauges attached on the girders, stringers, and intermediate diaphragms. The live-load was applied with two heavy trucks that were driven along three predetermined load paths. The calibrated finite-element model was used to quantify moment distribution factors and load ratings for the bridge. The finite-element distribution factors were compared to those calculated according to the American Association of State Highway and Transportation Officials (AASHTO) Standard and AASHTO Load and Resistance Factor Design (LRFD) Specifications. The distribution factors from both AASHTO codes were found to be unconservative for the girders and overly conservative for the stringers. The model was also used to quantify the effect of the transverse diaphragm members on the live-load distribution. Distribution factors were calculated with and without the diaphragm members. The diaphragms were found to increase the distribution of moments by over 20% for both positive and negative moments.

  • Record URL:
  • Supplemental Notes:
    • This research was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
  • Corporate Authors:

    Utah State University, Logan

    Department of Civil and Environmental Engineering, 4110 Old Main Hill
    Logan, UT  United States  84322-4110

    Utah Department of Transportation

    4501 South 2700 West
    Salt Lake City, UT  United States  84114-8410

    Center for Advanced Infrastructure and Transportation

    Rutgers University
    100 Brett Road
    Piscataway, NJ  United States  08854-8058

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Morrill, Jake L
    • Barr, Paul J
    • Halling, Marvin W
  • Publication Date: 2016-6


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 154p

Subject/Index Terms

Filing Info

  • Accession Number: 01674915
  • Record Type: Publication
  • Report/Paper Numbers: CAIT-UTC-NC12
  • Contract Numbers: DTRT13-G-UTC28
  • Created Date: Jun 28 2018 9:13AM