FATIGUE CRACKING IN MODULAR BRIDGE EXPANSION JOINTS

Single support bar modular expansion joints with 1200 mm of movement capability were used at each end of the Third Lake Washington Bridge between Seattle and Mercer Island on Interstate 90. Within 18 months after the bridge was open to traffic, cracks were observed in the tubular centerbeams of these large modular systems. Additional cracks have occurred since that date. Research was performed to determine the causes of the observed cracking and included an evaluation of existing methods for fatigue design of modular joint systems, finite element analyses of the large modular joints, and correlation of the results with observed behavior. The results show that the cracking is caused by fatigue due to repeated wheel loading. However, existing design methods may not be reliable indicators of the fatigue behavior because the behavior is influenced by the stiffness and dynamic response of the individual joint system. The variable span lengths complicate the evaluation process. The edge centerbeams have the longest and shortest alternating spans and have the highest percentage of fatigue cracks. The dynamic response of the modular joints is complicated because hundreds of vibrational modes contribute to the response, but theory suggests that the response is affected by joint type and loading. The single support bar system amplifies horizontal loads that are applied slowly, but it amplifies vertical loads through a wide range of vehicle speeds. The 1200-mm movement joints will require replacement before the expected design life of 25 to 30 years is achieved.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1994/1460/1460-011.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=FATIGUE+CRACKING+IN+MODULAR+BRIDGE+EXPANSION+JOINTS&author=C.+Roeder&author=M.+Hildahl&author=J.+Van+Lund&publication_year=1994
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1460, Structures. 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
• Authors:
  • Roeder, Charles W
  • Hildahl, Mark
  • Van Lund, John A
• Publication Date: 1994

Language

• English

Media Info

• Features: Figures; Photos; References;
• Pagination: p. 87-93
• Monograph Title: Structures: bridges, other structures, and hydraulics and hydrology
• Serial:
  • Transportation Research Record
  • Issue Number: 1460
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Beams; Bridge members; Cracking; Crash causes; Design methods; Dynamic loads; Expansion joints; Finite element method; Loads; Modular structures; Wheel loads
• Uncontrolled Terms: Amplification; Dynamic response; Horizontal loads; Vertical loads
• Old TRIS Terms: Centerbeams; Single support bar system
• Subject Areas: Bridges and other structures; Design; Highways; Safety and Human Factors; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00677570
• Record Type: Publication
• ISBN: 0309060672
• Files: TRIS, TRB
• Created Date: May 1 1995 12:00AM