Managing Florida's Fracture Critical Bridges - Phases I & II

Based on the definition given in the American Association of State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO LRFD) Bridge Design Specifications, twin steel box-girder bridges are classified as bridges with fracture critical members (FCMs), in which a failure of a tension member is expected to lead to a collapse of the bridge. However, a number of such bridges with either a partial or full-depth crack in one girder have been reported and are still providing service without collapsing. The main objective of this research project is to understand the behavior of twin steel box-girder bridges and to develop methods for evaluating their redundancy level in the event of the fracture of one tension member. The research project included an experimental investigation on a small-scale steel twin box-girder bridge, field testing of a full-scale twin box-girder, analysis of existing research and design data, and an extensive amount of numerical analyses carried out on calibrated 3-D nonlinear finite element models. The results from this study provide in-depth understanding of twin steel box-girder bridge behavior before and after a fracture in the tension member occurs. In addition to the experimentally verified finite element method, the report also proposes a simplified method for evaluating the performance of twin steel box-girder bridges and provides a list of important factors that could control the reserve capacity of the damaged bridge. A result of this project is the development of a comprehensive roadmap for assessing the redundancy of twin steel box-girder bridges in which the elements of the roadmap are identified, and solutions for several of the steps are provided. The development of solutions for remaining steps of the roadmap is proposed for a future research.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; References; Tables;
  • Pagination: 233p

Subject/Index Terms

Filing Info

  • Accession Number: 01603527
  • Record Type: Publication
  • Contract Numbers: BDV29-977-17
  • Created Date: Jun 14 2016 7:56AM