Modeling and Computing for Layered Pavements Under Vehicle Loading

Abstract

The objective of this research is to develop and implement some numerical models to analyze pavement responses under vehicle loading. Firstly, to study the pavement delamination problem, the pavement structure is modeled as an elastic finite layer system subjected to vertical and horizontal loadings over circular areas. By using the finite layer method, the maximum interface shear stress are determined; the maximum interface shear stress can be used to compare with the interface shear strength obtained through simple shear testing to determine reasonable pavement design parameters to prevent delamination failure. Secondly, the responses of a linear viscoelastic pavement system, with asphalt concrete layer of viscoelastic properties, subjected to vertical circular loadings, are analyzed by finite element method using three algorithms: (i) direct time integration; (ii) Fourier transform; (iii) Laplace transform. The inverse Fast Fourier Transform algorithm and the numerical inversion of Laplace transform method of Honig and Hirdes are used. The numerical results of the quasi-static responses by the three algorithms are presented and compared with respect to their accuracy and computational efficiency. To use the viscoelastic model in the pavement analysis, the parameters of the generalized Maxwell model based on the frequency sweep test results are determined by using the software IRIS, which is then assigned as the property of the asphalt concrete layer in a typical pavement structure subjected to a standard dual tire axle loading. Results for the distributions of stress and strain at various times are presented. In the last part of the research, a preliminary study is presented for permanent deformation of asphalt concrete. A simplified one-dimensional elasto-visco-plastic model is implemented and used to analyze the visco-plastic deformation of a cylindrical asphalt concrete sample under one-dimensional loading.

Description

Keywords

fatigue life, pavement delamination, permanent deformation, Laplace transform, viscoelastic model, Fourier transform, finite element method, elasto-visco-plastic model

Citation

Degree

PhD

Discipline

Civil Engineering

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