REDUNDANCY OF SIMPLE SPAN AND TWO-SPAN WELDED STEEL TWO-GIRDER BRIDGES. FINAL REPORT

To minimize the consequences of fracture of steel girder bridges AASHTO requires that reduced allowable fatigue stress ranges be used for nonredundant load path structures. Two-girder bridges are classified as nonredundant by AASHTO. The purpose of this investigation is to study the behavior of three real two-girder bridge spans, determine if redundant load paths exist, and if so, suggest design guidelines and procedures for ensuring redundancy of these two-girder study bridges. Elastic-plastic analyses of the two-girder study bridges were conducted. Lower bound incremental elastic-plastic finite element analyses were performed using the computer-integrated engineering system owned and operated by the Department of Civil Engineering, Lehigh University. Upper bound rigid-plastic analyses were performed using discontinuous virtual displacement fields to satisfy the mechanism condition. The use of computer graphics coupled with the finite element lower bound analyses was quite helpful in suggesting practical mechanisms for the upper bound analyses. Design procedures and guidelines were developed and used to redesign the study bridges to not only ensure redundancy but also to ensure after fracture serviceability of the study bridges. The results of this investigation suggest application of these design procedures and guidelines to other types and configurations of two-girder bridges as well as to multi-girder steel bridges.

• Corporate Authors:

  Lehigh University

  Fritz Engineering Laboratory
  Bethlehem, PA  United States  18015

  Pennsylvania Department of Transportation

  Office of Research and Special Studies, P.O. Box 2926
  Harrisburg, PA  United States  17120

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Daniels, J H
  • Wilson, J L
  • Chen, S S
• Publication Date: 1987-11

Media Info

• Features: Figures; References; Tables;
• Pagination: 279 p.

Subject/Index Terms

• TRT Terms: Beams; Computer graphics; Design methods; Elastoplasticity; Fatigue (Mechanics); Finite element method; Fracture mechanics; Guidelines; Metal bridges; Redundancy; Steel bridges; Structural analysis; Structural mechanics; Welds
• Uncontrolled Terms: Elastic plastic analysis; Fracture; Structural behavior; Two-girder bridges
• Old TRIS Terms: Simple span; Two-span; Welded steel beams
• Subject Areas: Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00464667
• Record Type: Publication
• Report/Paper Numbers: Proj 84-20, Fritz ELR No. 503.2
• Contract Numbers: 250008
• Files: TRIS, USDOT, STATEDOT
• Created Date: Dec 31 1987 12:00AM