DEFLECTION PREDICTION IN PROTOTYPE PAVEMENTS

AN APPROACH TO THE PROBLEM OF PREDICTING THE SURFACE DEFLECTION OF A SINGLE LAYER SYSTEM, REPRESENTING A SIMPLE PAVEMENT STRUCTURE ACTED ON BY A STATIC UNIFORM LOAD IS DESCRIBED. THIS METHOD IS BASED ON STRAIN MEASUREMENTS MADE ON TRIAXIAL SAMPLES LOADED UNDER STRESS CONDITIONS REPRESENTATIVE OF THOSE MEASURED WITHIN THE MASS. THE MEASUREMENT OF STRESSES WITHIN THE MASS ALLOWED COMPARISONS TO BE MADE WITH STRESSES PREDICTED BY THEORIES OF ELASTICITY. TESTS WERE CARRIED OUT ON AN AIR-DRY GRADED SAND CONTAINED IN A TANK 6 FT. BY 6 FT. BY 4 FT. 8 IN. HIGH. THE SURFACE WAS LOADED BY A 10-IN. DIAMETER FLEXIBLE MEMBRANE TO A MAXIMUM PRESSURE OF 30 P.S.I. AND DEFLECTIONS WERE RECORDED UNDER BOTH INITIAL AND REPEATED APPLICATIONS OF THE LOAD. STRESSES IN BOTH THE VERTICAL AND HORIZONTAL DIRECTION WERE MEASURED USING MINIATURE EARTH PRESSURE CELLS. THE SPECIAL TECHNIQUES USED TO CALIBRATE THE PRESSURE CELLS ARE DESCRIBED. RESULTS INDICATE THAT SURFACE DEFLECTIONS IN THE PROTOTYPE PAVEMENT UNDER FIRST-CYCLE LOADING CAN BE PREDICTED REASONABLY WELL, ALTHOUGH THE METHOD IS NOT SUITABLE AS A DESIGN TECHNIQUE BECAUSE OF THE REFINED EXPERIMENTAL MEASUREMENTS REQUIRED. THE STRESS MEASUREMENTS INDICATE THAT THE SIMPLE BOUSSINESQ ELASTIC THEORY IS INADEQUATE, PARTICULARLY FOR PREDICTION OF RADIAL STRESSES. IT IS SUGGESTED THAT CONSIDERATION OF ANISOTROPIC MATERIAL BEHAVIOR WOULD LEAD TO BETTER STRESS PREDICTION IN REAL MATERIALS.

• Supplemental Notes:
  • Prepring VoL, PP 573-591, 13 FIG, 28 REF
• Authors:
  • Morgan, J R
  • HOLDEN, J C
• Conference:
  • Intl Conf Struct Design Asphalt Pvmts
• Publication Date: 1967-1

Subject/Index Terms

• TRT Terms: Alternatives analysis; Anisotropy (Physics); Calibration; Deflection; Elasticity (Mechanics); Flexible pavements; Forecasting; Load cells; Materials; Pavement layers; Prototype tests; Strain measurement; Surfaces
• Old TRIS Terms: Anisotropy; Elastic theory
• Subject Areas: Highways; Materials; Pavements;

Filing Info

• Accession Number: 00206654
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 1 1994 12:00AM