CRITERIA FOR THE DEFLECTION OF STEEL BRIDGES

THE OBJECTIVES WERE TO DETERMINE THE ACTUAL EFFECTS OF SLENDERNESS AND FLEXIBILITY ON THE QUALITY OF MULTISTRINGER STEEL HIGHWAY BRIDGES AND TO RECOMMEND RATIONAL DESIGN CRITERIA. THE INVESTIGATION CONSIDERED EFFECTS OF FLEXIBILITY AND SLENDERNESS ON PEAK STRESSES, STRESS RANGES AND DEFLECTIONS DUE TO LIVE LOADS AND THEIR DYNAMIC EFFECTS. THESE EFFECTS ARE DIRECTLY RELATED TO GROSS YIELDING, DECK CRACKING, AND FATIGUE DAMAGE, AND ARE CORRELATED WITH POSSIBILITIES OF BRIDGE DECK DETERIORATION AND HUMAN DISCOMFORT FROM BRIDGE MOTIONS. DESIGN STUDIES INDICATE THE PREDICTED EFFECTS OF REVISED DEFLECTION CRITERIA ON THESE MODES OF BEHAVIOR. IT APPEARS THAT RELAXED CRITERIA FOR SLENDERNESS AND FLEXIBILITY WOULD HAVE NEGLIGIBLE OR BENEFICIAL EFFECTS FOR ALL MODES OF RESPONSE OTHER THAN HUMAN DISCOMFORT FROM BRIDGE MOTIONS. THERE SEEMS TO BE NO NEED FOR DEFLECTION CRITERIA IN THE ABSENCE OF PEDESTRIAN TRAFFIC. PEDESTRIAN DISCOMFORT DOES NOT APPEAR TO BE DIRECTLY RELATED TO THE PRESENT DEFLECTION CRITERIA. A REVIEW OF AVAILABLE INFORMATION SUGGESTS THAT A CRITERION FOR THE COMFORT OF PEDESTRIANS SHOULD LIMIT THE ACCELERATION IN THE FUNDAMENTAL MODE OF VIBRATION AT THE MIDSPAN REGION OF THE BRIDGE. THE ACCELERATION CRITERION OFFERS CONSIDERABLE POTENTIAL FOR ECONOMY IN DESIGN OF BRIDGES WHICH CARRY PEDESTRIAN TRAFFIC. /AUTHOR/

  • Supplemental Notes:
    • BULLETIN NO 19
  • Corporate Authors:

    American Iron and Steel Institute

    1101 17th Street, NW, Suite 1300
    Washington, DC  United States  20036-4700
  • Authors:
    • Wright, R N
    • Walker, W H
  • Publication Date: 1971-11

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 75 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00209725
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 31 1972 12:00AM