DETERMINATION OF THE STRUCTURAL CHARACTERISTICS OF PAVEMENTS FROM THE INFLUENCE LINE OBTAINED FROM THE LOADING TEST WITH TIRES

THE DIMENSIONING OF PAVEMENTS REINFORCEMENT HAS BEEN DIFFICULT BECAUSE OF THE NEED TO DETERMINE THE STRUCTURAL CHARACTERISTICS OF THE COMPLEX FOUNDATION SOILS-PAVEMENTS TO BE REINFORCED, ESPECIALLY THE MODULUS OF ELASTICITY OF THE LAYERS CONSTITUTING THIS COMPLEX. DETERMINATION OF THESE CHARACTERISTICS IS NORMALLY ACHIEVED BY LOADING TESTS WITH PLATES OF VARIED DIAMETERS, WHICH IS TIME CONSUMING. LOADING TESTS WITH TIRES HAVE NOT BEEN USED FOR THIS PURPOSE EVEN IF THEY ARE QUICKER AND EASIER TO BE CARRIED OUT THAN THE ONES WITH PLATES, DUE SPECIALLY TO THE DIFFICULTY IN ADEQUATE VARIATION OF THE DIAMETER OF THE LOAD APPLIED. IF, INSTEAD OF THE SIMPLE MEASUREMENT OF THE MAXIMUM REVERSIBLE DEFLECTION, COMMON IN THE LOADING TESTS WITH TIRES, ONE REGISTERS THE INFLUENCE LINE OF THE SETTLEMENTS, AS THE LOADED VEHICLE PASSES BY, ONE CAN COLLECT MUCH MORE INFORMATION AND IT TAKES LESS TIME. STRUCTURAL CHARACTERISITCS OF THE TESTED LAYERS WERE DETERMINED FROM THESE INFLUENCE LINES. AFTER STUDYING THE PRECISION OF THE LOADING TESTS AND VERIFYING THAT THE ROAD PERFORMANCE UNDER THE PRESSURE OF A ROLLING LOAD COULD BE CONSIDERED THE WHOLE TIME ELASTIC, AN ADEQUATE METHOD WAS SET WHICH ALLOWED COMPUTATION OF THE INFLUENCE OF LINES OF THE SURFACE SETTLEMENTS OF SYSTEMS CONSTITUTED OF 2 OR 3 ELASTIC LAYERS SUBJECT TO A CIRCULAR LOAD WHEN THE SETTLEMENT IN THE CENTER OF A CIRCULAR LOAD OF ANY RAY WAS KNOWN. THIS METHOD WA BASED ON ST. VENANT'S PRINCIPLE. THE RESULTS OF SOME OF THE COMPUTATIONS WERE SET IN TABLES TO INTERPRET THE EXPERIMENTAL INFLUENCE LINES. THE DETERMINATION OF THE STRUCTURAL CHARACTERISTICS OF THE COMPLEX FOUNDATION SOILS-PAVEMENTS BY COMPARISON BETWEEN THE EXPERIMENTAL INFLUENCE LINES WITH THE VALUES IN THE TABLES, FROM WHICH TWO EXAMPLES WERE PRESENTED WAS CARRIED OUT IN A DOZEN AND A HALF PAVEMENTS OF SEVERAL ROADS, COVERING A COMPLETE RANGE OF REVERSIBLE DEFLECTIONS AND THICKNESSES. AS VERIFICATION OF THE RESULTS, WERE COMPUTED FROM THE CHARACTERISTICS THUS DETERMINED, THE REVERSIBLE DEFLECTION IN THE CENTER OF THE PLATES OF VARIOUS DIAMETERS COMPARED WITH THE LOADING TESTS CARRIED OUT IN THE SAME PLACES WITH PLATES OF THE SAME DIAMETER. THE RESULTS OF THIS COMPARISON SHOWED AN ACCEPTABLE SIMILARITY BETWEEN THE MEASURED AND COMPUTED VALUES. /RRI/

  • Corporate Authors:

    Road Research Institute /Brazil

    ,    
  • Authors:
    • Pereira, O A
  • Publication Date: 1970

Subject/Index Terms

Filing Info

  • Accession Number: 00205879
  • Record Type: Publication
  • Source Agency: Road Research Institute /Brazil
  • Files: TRIS
  • Created Date: May 16 1971 12:00AM