This paper describes a concept for the fatigue evaluation and design of railroad bridges. The primary objective is to account for the number of stress cycles per train, the corresponding stress ranges, and the total number of trains in the lifetime of the structure. Stress recordings from various structural elements of existing bridges were used as input for fatigue tests on beams. The test results are evaluated using the rainflow counting method and Miner's cumulative damage law. These results show good correspondence with constant amplitude test data. The assessment of traffic is based on theoretical traffic models and on measurements of axle loads and axle spacings. The fatigue effect of the traffic models is simulated by computer programs in terms of span length and compared to field measurements. It is shown that a correction factor may be applied to the design live load when used for fatigue considerations. In addition, the fatigue design concept is able to account for the total number of trains in the lifetime of the bridge . Also, a different safety factor may be applied for redundant and nonredundant load path structures. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 86-92
  • Monograph Title: Bridge Engineering. Volume 1
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00183751
  • Record Type: Publication
  • ISBN: 0309026962
  • Files: TRIS, TRB
  • Created Date: Dec 3 1978 12:00AM