Existing dynamic load allowances or impact factors used for bridge design in a number of different countries around the world are surveyed and comparisons are made with the present requirements of the New Zealand bridge design brief. The fundamental vertical vibration frequencies of a range of typical New Zealand bridges were calculated and used to provide a comparison between the present allowance for impact factor based on span length and that of the Ontario highway bridge design code based on vertical vibration frequency. Mean values for the impact factors measured on several New Zealand bridges are included for comparison. The use of an impact factor along the lines of that used in the Ontario bridge design code would seem to be desirable in that it makes better provisions for impact in the range of spans (or bridge frequencies) where bridge-vehicle interaction is likely to be a problem. (TRRL)

  • Availability:
  • Corporate Authors:

    University of Canterbury

    Department of Civil Engineering, Private Bag 4800
    Christchurch,   New Zealand  8140
  • Authors:
    • Carr, A J
    • Moss, P J
  • Publication Date: 1982-5

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00384562
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Report/Paper Numbers: 82-14 Monograph
  • Files: ITRD, TRIS
  • Created Date: May 30 1984 12:00AM