A twofold methodology for the evaluation of overlaod vehicles is developed. First, a simple formula has been developed which relates axle weights and spacings to the maximum permissible load. This formula was calibrated using the AASHTO girder-line analyses of 104 typical structures with 20 overload and design vehicles. The resulting analyses were used to create a database upon which the base correlation, multivariable regression, and sensitivity analyses. The analyses were based on AASHTO state-of-practice procedures using the stresses at the operating rating level. Secondly, an automated approach is being developed which is based on a graphical information system that links truck, route, and structure data to perform ratings of all structures along a requested route. The analysis method is identical to the present procedures used by the rating engineer (hereafter referred to as the Rational Method). This aspect of the rating approach is presently in the implementation phase and is briefly described below. In the formula development, numerous bridge, vehicle, and bridge/vehicle parameters were correlated with the maximum load which can be sustained at the operating level. The only statistically significant parameter was determined to be the maximum out-to-out dimension of the load group length parameter, herein called the axle length. The axle length was used to develop a statistically-based formula for the prediction of maximum load capacity for a particular axle weight distribution. Because no useful formula can work conservatively 100 percent of the time, the confidence levels of 90, 95, and 99 percent were formulated. The route is determined by a mapping system which contains pointers to each roadway segment in the state. This pointer toggles to indicate the vehicle route.

  • Corporate Authors:

    University of Wyoming, Laramie

    Wyoming Survey and Analysis Center, 710 Garfield
    Laramie, WY  United States  82070
  • Authors:
    • Puckett, J A
    • Lieber, S R
  • Publication Date: 1990-11

Media Info

  • Pagination: 111 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00616052
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA/WY-90/001
  • Files: TRIS
  • Created Date: Oct 31 1991 12:00AM