Seismic Behavior of Steel Bridges with Fatigue-Prone Details

Steel bridges with reinforced concrete substructures and steel superstructures are considered to have superior performance under earthquakes when compared with their reinforced concrete counterpart. Such performance reputation stems from the fact that few steel bridges have been subjected to strong ground motion in the last decade in North America. In addition to the lack of seismic exposure of bridges, research on the seismic performance of steel bridges’ superstructure is limited to handful of studies. It is noteworthy that none of the previously conducted studies addressed the behavior of the bridge superstructure’s fatigue details, which are designed for traffic loading, under earthquake loading. The studies also did not address the potential for the presence of existing cracks in bridges when an earthquake occurs. In the superstructure, fatigue is often the most prevalent problem in steel bridges and contributes to approximately 90% of existing cracks. The cracks are a result of the repeated traffic cycles exerted on the bridge, which is a primary concern in older bridges. In this study, the seismic behavior of a twin tub steel girder bridge is evaluated. Specifically, a detailed finite element model of the bridge in question is developed, and the model is subjected to a suite of ground motions. Of the two models developed, one did not include any initial cracks and one included a crack that presumably developed because of fatigue loading from usual traffic. The results of the analysis show large displacement of the bridge due to exposure to some of the earthquakes. In addition, the results show the potential for developing low cycle fatigue failure in some of the details, even in the absence of an initial crack. These results are critical as they highlight the importance for detailed assessment of the superstructure for bridges in moderate to high seismic regions.

• Record URL:
  https://www.ugpti.org/resources/reports/details.php?id=944
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/42707
• Summary URL:
  https://rosap.ntl.bts.gov/view/dot/42708
• Supplemental Notes:
  • This document was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
• Corporate Authors:

  Colorado State University, Fort Collins

  Department of Civil and Environmental Engineering
  Fort Collins, CO  United States  80525

  Mountain-Plains Consortium

  North Dakota State University
  Fargo, ND  United States  58108

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Authors:
  • Mahmoud, Hussam
  • Irfaee, Mazin
  • Hassan, Emad M
• Publication Date: 2018-9

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 32p

Subject/Index Terms

• TRT Terms: Bridge superstructures; Cracking; Dislocation (Geology); Earthquake resistant design; Fatigue (Mechanics); Finite element method; Girder bridges; Reinforced concrete; Seismicity; Steel bridges
• Subject Areas: Bridges and other structures; Highways; Maintenance and Preservation;

Filing Info

• Accession Number: 01710548
• Record Type: Publication
• Report/Paper Numbers: MPC-18-368
• Contract Numbers: MPC-382
• Files: UTC, NTL, TRIS, ATRI, USDOT
• Created Date: Jul 9 2019 11:27AM