CRACKING, FRACTURE ASSESSMENT, AND REPAIRS OF GREEN RIVER BRIDGE, I-26

The Green River Bridge, I-26 near Asheville, North Carolina, was opened to traffic in 1969. In October 1992, during an inspection, two long transverse cracks were discovered in the bottom flange plate of a main girder; these cracks resulted in closure of the eastbound bridge. Numerous shorter cracks were observed at the web to flange plate connecting fillet welds throughout the girders. The Green River Bridge is a five-span, twin structure having a total length of 320 m (1,050 ft). Each bridge is a two-girder system, and ASTM A441 modified Corten B weathering steel was used to fabricate the bridge. The investigation into the cause of the cracking included metallographic and fractographic examination of core samples containing cracks, chemical composition and toughness testing of material, and instrumentation and field testing to determine live load stress levels. Test results of the flange plate material containing the large cracks showed it to have high carbon content, large grain structure, very low toughness, and high hardness. A field hardness survey was carried out on all bottom flange plates to determine locations of plates in the structure with similar properties. The fatigue and fracture assessment found that the cracks discovered in the Green River Bridge occurred at the time of fabrication. All cracks appeared to result from hydrogen-related cold cracking. Orientation of the large cracks was influenced by welding residual stresses that caused the crack tip to turn to a nearly horizontal orientation (parallel to the stress field). Because of this favorable crack tip orientation, the large cracks could tolerate dead and live load stresses and fatigue crack growth and brittle fracture were prevented. The main retrofit recommendation was to bolt cover plates on all bottom flange plates subjected to tensile stresses using high-strength bolts. This retrofit will provide internal redundancy in all spans and reduce live load stress range levels in the two-girder system by about 50%. Repairs were completed in October 1994.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/conf/1995/cp7/cp7v2-001.pdf
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309061091
• Supplemental Notes:
  • Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Fisher, J W
  • Kaufmann, E J
  • Koob, M J
  • White, G
• Conference:
  • Fourth International Bridge Engineering Conference
  • Location: San Francisco, California
  • Date: 1995-8-28 to 1995-8-30
• Publication Date: 1995

Language

• English

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 3-14
• Monograph Title: FOURTH INTERNATIONAL BRIDGE ENGINEERING CONFERENCE, SAN FRANCISCO, CALIFORNIA, AUGUST 28-30, 1995. CONFERENCE PROCEEDINGS, 2 VOLUMES
• Serial:
  • Transportation Research Board Conference Proceedings
  • Issue Number: 7
  • Publisher: Transportation Research Board
  • ISSN: 1073-1652

Subject/Index Terms

• TRT Terms: Bolts; Cold weather; Conferences; Cracking; Flanges; Fracture mechanics; Girder bridges; Live loads; Plates (Engineering); Repairing; Retrofitting; Stresses; Transverse cracking; Weathering steel
• Uncontrolled Terms: Cold cracking; Reduction (Decrease); Repairs
• Old TRIS Terms: Cover plates; Flange plates; High strength bolts
• Subject Areas: Highways; Maintenance and Preservation; I61: Equipment and Maintenance Methods;

Filing Info

• Accession Number: 00711706
• Record Type: Publication
• ISBN: 0309061091
• Files: TRIS, TRB
• Created Date: Sep 6 1995 12:00AM