PERFORMANCE EVALUATION OF BACKCALCULATION ALGORITHMS THROUGH THREE-DIMENSIONAL FINITE-ELEMENT MODELING OF PAVEMENT STRUCTURES

Currently, the only means of assessing the performance of a backcalculation algorithm is to compare its results with the values obtained through laboratory measurements of core samples. Discrepancies are attributed to the inability of replicating in laboratory tests the same consolidation and stress conditions encountered in the field. In this paper, an explicit three-dimensional (3D) finite-element model (FEM) is used to backcalculate the layer moduli of rigid, flexible, and composite pavement structures. The modeling approach accounts for the dynamic nature of the falling weight deflectometer (FWD) load, friction at pavement-layer interfaces, and the 3D geometrical characteristics of the pavement structure. The FWD-measured and FEM-generated deflection basins are matched by adjusting the values of layer moduli used in the FEM. The backcalculated moduli using 3D FEM are compared with the results obtained from three backcalculation programs: MODCOMP, MODULUS, and EVERCALC. The results indicate that the three programs have an excellent capability of predicting the FEM-generated subgrade modulus values for flexible, composite, and rigid pavements provided that a correction factor is used. A correction factor for backcalculated subgrade modulus is estimated for each program and pavement type. The mechanistically evaluated correction factors were found to be in close agreement with the experience-based values recommended for flexible and rigid pavements in the American Association of State Highway Officials pavement design guide.

• Record URL:
  • https://doi.org/10.3141/1655-20
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=PERFORMANCE+EVALUATION+OF+BACKCALCULATION+ALGORITHMS+THROUGH+THREE-DIMENSIONAL+FINITE-ELEMENT+MODELING+OF+PAVEMENT+STRUCTURES&author=S.+Shoukry&author=G.+William&publication_year=1999
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309070511
• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1655, Pavement Management Systems and Other Pavement Design Issues.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Shoukry, S N
  • William, G W
• Publication Date: 1999

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 152-160
• Serial:
  • Transportation Research Record
  • Issue Number: 1655
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Algorithms; Alternatives analysis; Backcalculation; Composite pavements; Computer programs; Deflection; Falling weight deflectometers; Finite element method; Flexible pavements; Modulus of resilience; Pavement subgrade; Performance evaluations; Rigid pavements
• Uncontrolled Terms: Correction (Mathematics); Three dimensional models
• Subject Areas: Data and Information Technology; Design; Highways; Pavements; I22: Design of Pavements, Railways and Guideways; I23: Properties of Road Surfaces;

Filing Info

• Accession Number: 00769350
• Record Type: Publication
• ISBN: 0309070511
• Files: TRIS, TRB, ATRI
• Created Date: Sep 2 1999 12:00AM