AN EXPERIMENTAL ANALYSIS OF TRANSIENT VEHICLE LOADS AND RESPONSE OF FLEXIBLE PAVEMENTS

THE DEVELOPMENT AND APPLICATION OF EQUIPMENT AND TECHNIQUES FOR MEASURING SIMULTANEOUSLY THE DYNAMIC LOADS APPLIED TO A PAVEMENT BY A MOVING VEHICLE AND THE DYNAMIC STRESSES AND DISPLACEMENTS INDUCED BY THAT LOAD IN A FLEXIBLE PAVEMENT AND ITS SUBGRADE ARE DESCRIBED. DYNAMIC LOADS WERE MEASURED BY MONITORING THE FLUCTUATIONS IN TIRE INFLATION PRESSURE. STRESSES WERE MEASURED WITH A CELL INCORPORATING THE FLEXIBLE DIAPHRAGM PRINCIPLE. DISPLACEMENTS WERE SENSED WITH AN ACCELERATION SENSITIVE TRANSDUCER. AN ELECTRONIC ANALOG DEVICE WAS USED TO OBTAIN THE FIRST INTEGRAL OF THE ACCELERATION SIGNAL, AND A NUMERICAL INTEGRATION OF THAT RESULT WAS USED TO OBTAIN DISPLACEMENT. DATA WERE OBTAINED FROM THREE PAVEMENTS OF DIFFERING STIFFNESS CONSTRUCTED OVER SIMILAR SUBGRADES. IN EACH PAVEMENT, STRESS AND DISPLACEMENT TRANSDUCERS, MOUNTED TOGETHER AS A SINGLE UNIT, WERE PLACED AT THE SURFACE-BASE INTERFACE, THE BASE-SUBGRADE INTERFACE, AND IN THE SUBGRADE THREE FEET FROM THE SURFACE. A SINGLE-AXLE DUMP TRUCK LOADED TO 9,000 POUNDS ON EACH DUAL WHEEL, WAS OPERATED OVER THE TEST SECTIONS AT SPEEDS RANGING FROM 5 TO 60 MPH. PLOTS OF STRESS AND DISPLACEMENT ARE PRESENTED IN WHICH AN IMPORTANT DEPENDENCE ON LATERAL POSITION OF THE TEST VEHICLE IS APPARENT. TRENDS OF STRESS AND DISPLACEMENT AS A FUNCTION OF VEHICLE VELOCITY ARE ALSO INDICATED. STATISTICAL CURVE FITTING TECHNIQUES WERE USED TO FIT THE DATA TO A MODEL WHICH RELATES PEAK STRESS AND DISPLACEMENT TO INSTANTANEOUS LOAD AT THE TEST POINT, LATERAL POSITION OF THE VEHICLE AND VEHICLE VELOCITY. RESULTS ARE PRESENTED WHICH INDICATE THAT DYNAMIC EFFECTS OF LOAD ON PAVEMENT RESPONSE WERE UNIMPORTANT IN THE CASE OF THE VEHICLE AND PAVEMENTS IN THIS STUDY. USING THE FITTED EQUATIONS, PREDICTED VALUES OF STRESS AND DISPLACEMENT WERE OBTAINED FOR PARTICULAR VALUES OF LOAD AND VEHICLE POSITION AS A FUNCTION OF VEHICLE VELOCITY. THE RATIOS OF AVERAGE VERTICAL STRESS TO AVERAGE VERTICAL STRAIN IN THE BASE COURSE AND IN THE SUBGRADE WERE COMPUTED FROM PREDICTED VALUES OF STRESS AND DISPLACEMENT AND THE VARIATION OF THESE RATIOS WITH VEHICLE VELOCITY IS DEMONSTRATED.

  • Supplemental Notes:
    • Hpr-1/3/, III, BPR 8
  • Corporate Authors:

    Purdue University

    School of Aeronautics and Astronautics
    West Lafayette, IN  United States  47907
  • Authors:
    • Sanborn, J L
  • Publication Date: 1965-9

Subject/Index Terms

Filing Info

  • Accession Number: 00206271
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 1 1994 12:00AM