DEVELOPING A SET OF CBR DESIGN CURVES

ALTHOUGH THE CBR METHOD OF DESIGN OF FLEXIBLE PAVEMENTS IS ESSENTIALLY EMPIRICAL, DEVELOPMENTS HAVE LED TO THE ESTABLISHMENT OF A DISTINCT PATTERN FOR DESIGN RELATIONS. FROM THIS PATTERN, STANDARD PROCEDURES HAVE BEEN EVOLVED FOR CONSTRUCTING ANY DESIRED SET OF CBR DESIGN CURVES. THE CBR PATTERN IS PORTRAYED BY EITHER THE CBR EQUATION OR THE COMBINED CBR CURVE. EITHER PRESENTS A SINGLE RELATION (EQUATION OR CURVE) THAT IS ESSENTIALLY A COMBINATION OF ALL EMPIRICALLY DEVELOPED CBR DESIGN CRITERIA RESULTING FROM CORPS OF ENGINEERS RESEARCH. PREVIOUS STUDIES HAVE SHOWN THAT EITHER PORTRAYAL TRULY PRESENTS THE CBR PATTERN IN THE LOW CBR RANGE FOR SINGLE-WHEEL LOADS. THIS REPORT SHOWS HOW, BEGINNING WITH THE PATTERN FOR THE LOW CBR RANGE, THE COMBINED CBR CURVE, SUPPLEMENTED BY RELATED INFORMATION AND JUDGMENT, CAN BE USED TO EXTEND SINGLE-WHEEL RELATIONS INTO THE HIGH CBR RANGE. IT ALSO SHOWS HOW, BY THE USE OF EQUIVALENT SINGLE-WHEEL LOADS, THE SINGLE-WHEEL DESIGN CRITERIA CAN BE APPLIED TO ANY MULTIPLE-WHEEL CONFIGURATION. FINALLY, MEANS ARE INDICATED FOR FURTHER EXTENDING EITHER SINGLE- OR MULTIPLE-WHEEL DESIGN CRITERIA TO CRITERIA FOR INTENSE USE OR FOR VARIOUS LEVELS OF LIMITED USE BASED ON LOAD REPETITIONS. AN APPENDIX PROVIDES A DETAILED EXAMPLE OF THE METHOD BY WHICH THE THEORETICAL MAXIMUM DEFLECTIONS ARE DEVELOPED FOR SINGLE- AND MULTIPLE-WHEEL ASSEMBLIES AND COMBINED TO ESTABLISH A RELATION BETWEEN MULTIPLE-AND SINGLE-WHEEL LOADS. /AUTHOR/

  • Supplemental Notes:
    • Instruction REPORT NO 4, VII + 10 PP, 9 FIG, 3 TAB, 7 REF,
  • Corporate Authors:

    U.S. Army Waterways Experiment Station

    3909 Halls Ferry Road
    Vicksburg, MS  USA  39180-6199
  • Publication Date: 1959-11

Subject/Index Terms

Filing Info

  • Accession Number: 00205512
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 13 1994 12:00AM