Effects of layer interface slip on the response and performance of elastic multi-layered flexible airport pavement systems

Abstract

In this study, the effect of layer interface slip rate on the critical responses such as (primary) tensile strains as well as strain distortion energies for a flexible runway pavement structure is examined based on strain energy of distortion. The strain energies have, in recent years received attention as an indication of potential fatigue and or damage failure criteria. Important environmental effects such as pavement moisture and temperature were, however, not analytically considered in this study. The new AASHTO pavement design guide for flexible pavements is shifting from an experience (or purely empirical) based design method to a mechanistic-empirical (M-E) design method. The latter approach requires an elastic multi-layered analysis to compute responses of interest and use empirically established models to determine airport pavement distresses like fatigue cracking of asphalt concrete layer and as well as rutting or plastic deformation. Three different types of compliance models that simulate pavement layer interface slip and introduced into the multi-layered elastic analysis freeware known as GAMES are presented in this paper. The GAMES software is capable of analyzing effects of five different types of airport pavement surface loading, namely; vertical, horizontal (shear), torsion, moment and centripetal forces. Airport pavement responses due to multiple loadings are determined by using the superposition concept applicable to linear elastic theory, where responses from each wheel load are decomposed into the x-y-z components before summing-up the responses at each point.