محمود ملکوتی علون آبادی

Road pavements, due to a long history in the world and also in Iran, has long been a concern for engineers. Gradually and with the forming a standard format for flexible pavements, making computer programs and numerical analysis of pavements to spend less time and scrutiny, is quite inevitable. The analysis of road pavements responses such as displacements, strains and stresses resulting from imposed impulsive loads, is one of the most important issues in pavement design. Various methods such as finite element, finite difference etc. can be used for analysis of this problem, but, as in all matters, the main goal is to reach high accuracy while spending less time for analysis, in this research, a new method of differential quadrature is used. In most studies conducted to date, flexible pavement behavior is considered as elastic but the asphalt layer on top of the flexible pavements, behave as a viscoelastic material. In this study, first, by using the Boltzmann integral characteristic equation and Maxwell-Wiechert generalized model for modeling the viscoelastic behavior and using an incremental algorithm, equations of equilibrium for one-dimensional and two-dimensional (plane stress and axisymmetry) is obtained. Then, by discritizing the differential equations using differential quadrature method, modeling of one-dimensional and two-dimensional (plane stress and axisymmetry) problems is carried out and the results of this method compared with the analytical solution and ABAQUS software. Finally, the axisymmetric viscoelastic flexible pavement system under sinosoidal or cyclic-sinosoidal loading, have been analyzed in quasi-static mode or dynamically.