PLANNING PROJECT FOR DEVELOPMENT OF PROCEDURES FOR THE ANALYSES OF WEIGHT DISTRIBUTION DATA TO CALCULATE EQUIVALENT LOADS

IT WAS THE PURPOSE OF THIS PROJECT TO DETERMINE EQUIVALENCIES FOR TRIDEM TYPE AXLE LOADS. THIS INVOLVED AN INVESTIGATION OF WHAT EQUIVALENCY VALUES ARE APPROPRIATE AND HOW THEY SHOULD VARY WITH AXLE SPACING. TYPICAL PAVEMENT SECTIONS UNDER TWO CLIMATIC CONDITIONS WERE SIMULATED USING ELASTIC THEORY. CRITERIA USED TO DETERMINE LOAD EQUIVALENCIES FOR THE STUDY ARE DESCRIBED. FIGURES ILLUSTRATING TYPICAL STRAIN CURVES DUE TO A TRIDEM AXLE LOADING ARE PRESENTED. RECOMMENDED EQUIVALENCY FACTORS FOR PARTICULAR GROSS AXLE LOADS ARE TABULATED. THE SECOND HALF OF THE PROJECT INVOLVED THE DEVELOPMENT OF A COMPUTER PROGRAM WHICH WOULD CONVERT RAW WEIGHT DATA INTO A STANDARD TABULAR FORM AND CALCULATE N-18 FACTORS FOR EACH VEHICLE. STEPS IN THE CALCULATION OF N-18 ARE LISTED. THE THREE COMPUTER PROGRAMS USED TO COMPUTE THE EQUIVALENCY FACTORS FOR SINGLE, TANDEM AND TRIDEM AXLE LOADS ARE: N-LAYER ELASTIC SYSTEM PROGRAM, TRIDEM PROGRAM, AND FACTOR PROGRAM. CONDITIONS USED TO CALCULATE EQUIVALENCY FACTORS ARE DESCRIBED AND EQUIVALENCY FACTORS CALCULATED USING THE METHOD AND CONDITIONS DESCRIBED ARE GRAPHICALLY REPRESENTED. THE VARIATION OF CALCULATED EQUIVALENCIES FOR THE DIFFERENT SIMULATED CONDITIONS, THE RELATIONSHIP BETWEEN AXLE LOAD, SPACING, AND EQUIVALENCY FACTOR FOR THE VARIOUS PAVEMENT TYPES AND CLIMATIC CONDITIONS AND THE VARIATION OF EQUIVALENCIES USING THE SUBGRADE VERTICAL STRAIN CRITERIA, ARE ALL ILLUSTRATED. THE COMPUTED OVERALL EQUIVALENCY FACTORS FOR DESIGN ARE DISCUSSED.

  • Corporate Authors:

    Minnesota Department of Highways

    ,    
  • Publication Date: 1971-9

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 52 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00206078
  • Record Type: Publication
  • Report/Paper Numbers: Final Rept
  • Files: TRIS, STATEDOT
  • Created Date: Jan 11 1974 12:00AM