Analysis and design of two layered flexible pavement systems: A new mechanistic approach

Abstract

Analysis of two layered flexible pavements is considered as a significant aspect for design of low volume roads, which typically consist of a thick granular base course directly laid over subgrade with or without a thin asphalt-wearing course. Permanent deformation or rutting has been observed to be the major distress mode in thin surfaced or unsurfaced low volume roads. In the present study, a new formulation has been proposed to determine the surface and interface deflections for both single and standard axle dual wheel assembly for a two layered pavement system. The present formulation has been developed based on mechanistic approach and the solutions obtained from 3-dimensional finite element program, using ABAQUS taking into account the influence of rectangular tire imprint, modulus of granular base course, pavement thickness and ratio of modulus of pavement and subgrade. The effect of Poisson’s ratio of granular base and subgrade is observed to be very insignificant. For the estimation of surface and interface deflections, deflection factors have been generated in the form of non-dimensional charts as a function of ratio of modulus of pavement and subgrade, and ratio of pavement thickness and tire width.