DETERMINATION OF THE STRUCTURAL CHARACTERISTICS OF ROAD PAVEMENTS FROM INFLUENCE LINES OF THE REVERSIBLE SETTLEMENTS UNDER A MOVING WHEEL LOAD

PAVEMENT STRENGTHENING DESIGN HAS BEEN MADE DIFFICULT BY THE NEED TO OBTAIN THE STRUCTURAL CHARACTERISTICS OF THE SET "SOIL-PAVEMENT TO BE STRENGTHENED" PARTICULARLY AS REGARDS THE MODULI OF ELASTICITY OF THE COMPONENT LAYERS. THESE VALUES ARE USUALLY DETERMINED BY MEANS OF FAIRLY TIME-CONSUMING BEARING TESTS ON PLATES OF DIFFERENT DIAMETERS. ALTHOUGH QUICKER AND EASIER THAN PLATE-BEARING TESTS, PAVEMENT DEFLECTION TESTS UNDER A MOVING WHEEL HAVE NOT BEEN USED FOR THIS PURPOSE DUE PRIMARILY TO THE DIFFICULTY IN SUITABLY CHANGING THE DIAMETER OF THE APPLIED LOADS. IT IS POSSIBLE, HOWEVER, TO OBTAIN VERY VALUABLE DATA IF, INSTEAD OF MERELY MEASURING THE MAXIMUM REVERSIBLE DEFLECTION AS IS USUAL IN PAVEMENT DEFLECTION TESTS, THE INFLUENCE LINE OF REVERSIBLE SETTLEMENTS UNDER THE LOADING VEHICLE IS PLOTTED, WHICH DOES NOT REQUIRE MORE TIME. THE STRUCTURAL CHARACTERISTICS OF THE TESTED LAYERS FROM THESE INFLUENCE LINES ARE DETERMINED. THE ACCURACY OF BEARING TESTS IS STUDIED AND IT IS VERIFIED THAT THE BEHAVIOR OF ROADS UNDER A MOVING LOAD CAN BE CONSIDERED AS ELASTIC, AT EVERY MOMENT. A METHOD IS DEVELOPED OF CALCULATION BASED ON ST. VENANT'S PRINCIPLE, BY MEANS OF WHICH IT IS EASY TO OBTAIN THE INFLUENCE LINE OF THE SETTLEMENTS AT THE SURFACE OF SYSTEMS OF TWO AND THREE LAYERS, UNDER A CIRCULAR LOAD, WHEN THE SETTLEMENTS IN THE CENTER OF THE LOAD ARE KNOWN. THE CORRESPONDING RESULTS, FOR A RANGE OF ABOUT 50 CASES OF TWO-LAYER SYSTEMS AND 200 CASES OF THREE-LAYER SYSTEMS ARE ALSO PRESENTED, IN TABLES ALLOWING THE INTERPRETATION OF THE INFLUENCE LINES. THE STRUCTURAL CHARACTERISTICS OF ABOUT FIFTEEN ROAD PAVEMENTS COVERING A QUITE COMPREHENSIVE RANGE OF REVERSIBLE DEFLECTIONS AND THICKNESSES WERE THEN DETERMINED BY COMPARISON OF THE EXPERIMENT INFLUENCE LINES WITH VALUES FROM THE TABLES. AS A CHECK ON THE RESULTS OBTAINED, REVERSIBLE DEFLECTIONS AT THE CENTER OF PLATES WITH DIFFERENT DIAMETERS WERE CALCULATED FROM THE CHARACTERISTICS DETERMINED, AND THE VALUES WERE COMPARED WITH THE RESULTS OF PLATE-BEARING TESTS IN THE SAME PLACES WITH PLATES OF THE SAME DIAMETERS. THE RESULTS OF THIS COMPARISON SHOW A SATISFACTORY AGREEMENT BETWEEN MEASURED AND CALCULATED VALUES. /LCPC/RRL/

• Supplemental Notes:
  • Vol 1, 55 PP, 6 FIG, 2 TAB, 2 PHOT, 56 REF, APPS
• Corporate Authors:

  Nat Lab Civil Eng, Lisbon /Port

  ,    
• Authors:
  • Pereira, O A
• Publication Date: 1969-8

Subject/Index Terms

• TRT Terms: Deflection; Durability; Ground settlement; Influence lines; Modulus of elasticity; Pavement design; Pavement performance; Pavements; Plate bearing test; Structural analysis; Wheel loads
• Old TRIS Terms: Highway pavement; Pavement deflection
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 00206852
• Record Type: Publication
• Source Agency: Road Research Laboratory /UK
• Files: TRIS
• Created Date: Sep 28 1970 12:00AM