VALIDATION OF THREE DIMENSIONAL NONLINEAR FINITE ELEMENT MODEL USING CANTERBURY ACCELERATED PAVEMENT TEST TRACK (CAPTIF)

This paper describes how, ABAQUS, a general-purpose finite element software package, was used in order to simulate the pavement response in the Canterbury Accelerated Pavement Testing Indoor Facility (CAPTIF). A three-dimensional non-linear finite element (3D-FEM) model was developed in order to model the pavement structure. The stress dependency of the base course and the subgrade were investigated in the laboratory and accounted for in the numerical simulation. The plasticity of the pavement materials was considered by using the Drucker-Prager constitutive model in the finite element simulation. The measured strains, interface stresses and deflections were measured in the instrumented test track. In addition, two multilayer elastic models were used for the purpose of comparison with the finite element simulation and the actual measurements. The first elastic multilayer model was developed using ELSYM5, and the second model was developed using CIRCLY. CIRCLY can account for the anisotropy of the pavement materials while ELSYM5 considers the pavement materials to be isotropic. The actual strains and deformations were measured using Emu strain gauges imbedded at different depths in the base and subgrade materials. Both the unbound granular base and the subgrade materials were modelled in the 3DFEM as elastic-plastic materials. The results of this study showed that for the unbound base layer, the calculated strains from the two elastic models were in reasonable agreement with the measured values in the instrumented test track, while the 3D-FEM model tended to over estimate the strains at the bottom of the base layer. While none of the models provides a perfect fit to the measured strains in the subgrade layer due to the subgrade being less homogenous than assumed, the 3D FEM looks most promising as it provides the closest fit to the measured strain values. Also, it was clear that considering the anisotropy of the materials provides better results than the isotropic solution.

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  • English

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  • Accession Number: 00964270
  • Record Type: Publication
  • ISBN: 087659229X
  • Files: TRIS, ATRI
  • Created Date: Oct 3 2003 12:00AM