A NEW LINEAR ELASTIC BACK-CACULATION MODEL FOR BACK-CALCULATING LAYER MODULI AT FIXED POISSON'S RATIOS

In this paper a new model, namely EFROMD-II, for back-calculating linear moduli from pavement deflection bowls is presented. The model uses CIRCLY in the iterative process and adopts a new iterative technique for back-calculating layer moduli at fixed Poisson's ratios as suggested in the NAASRA Pavement Design Guide. It has been verified by using the response of a hypothetical pavement consisting of four layers with known elastic properties as input. Comparison between the efficiency and accuracy of EFROMD-II and the current EFROMD-I model has shown that EFROMD-II took only 5-10 % of the computing time of EFROMD-I, depending on the level of accuracy in the back-calculated solutions. In the case where equilibrium cannot be achieved in the iterative process, the criteria for selecting the final solutions (moduli and critical strains) in the models can be described in terms of a maximum "partially-converged" average error in deflection, below which the solutions reduce monotonically with increasing number of iterations and also reduce linearly with reducing average errors in deflections. For the case stuied, at the maximum "partially-converged" average error in deflections of 0.5 per cent, EFROMD-II produced up to 22% errors in the moduli of the middle layers, 17% error in the critical tensile strain and less th 4% errors in other layer moduli and in the subgrade critical strain. Further studies of pavements of different configurations and of non-linear material properties are necessaray to obtain a comprehensive comparison and tests of sensitivity.

• Record URL:
  • http://arrbknowledge.com
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00050164
• Authors:
  • VUONG, B
• Publication Date: 1989-3

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 17-28
• Serial:
  • Australian Road Research
  • Volume: 19
  • Issue Number: 1
  • Publisher: ARRB
  • ISSN: 0005-0164

Subject/Index Terms

• TRT Terms: Accuracy; Deflection; Iterative methods; Mathematical models; Modulus of elasticity; Pavement layers; Pavements; Poisson ratio; Subgrade (Pavements); Tension
• Old TRIS Terms: Pavement deflection; Poissons ratio
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 00484743
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 30 1989 12:00AM