A NEW LINEAR ELASTIC MODEL FOR BACK-CALCULATING LAYER MODULI AND POISSON'S RATIOS

In this paper a new algorithm back-calculating model, EFROMD-II, for back-calculating layer Young's moduli and Pois son's ratios is presented. A pavement consisting of four elastic layers: an asphalt layer, an unbound base, an unbound sub-base and a subgrade of CBR 10, was used to verify the algorithm. It is demonstrated that the back-calculated solutions (moduli and critical strains for predicting pavement life), except the subgrade modulus, can be very sensitive to errors in both surface deflections and in Poisson's ratios. For the case studied, the errors in the calculated deflections must be less than 0.2 percent in order to obtain less than 20 percent errors in the back-calculated moduli of upper layers and about 5 to 10 percent errors in the back-calculated critical strains. An error in subgrade Poisson's ratio of 0.05 produced up to a 25 percent error in the moduli of the upper layers and about an 8 percent error in the subgrade critical strain. Further studies of pavements of different configurations and of non-linear material properties are necessary to obtain more comprehensive tests of sensitivity.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 288-297
  • Serial:

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Filing Info

  • Accession Number: 00495211
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: TRIS, ATRI
  • Created Date: Jul 31 1990 12:00AM