Multilayered elastic analysis formulation for surface moment loading

Abstract

When pavement structures like roads and runways are under simultaneous actions of vehicular vertical and horizontal wheel loading, analysis is normally performed considering these loads as uniformly distributed vertical and horizontal loads, respectively. Measurements by Stress-In-Motion (SIM) technology on slow (creep) speed truck tires have shown that, depending on the magnitude of the load, there are acceptable "n" or unacceptable "m" shaped stress distributions at the tire/road interface. In order for accurate mathematical derivation of, for example, non-uniform "m" shaped surface stress to be performed, authors have proposed introduction of a moment-like surface loading. Detailed derivation of closed form solutions of pavement response due to the action of non-uniform circular loading is presented in this paper. Results show that maximum compressive stress at the pavement surface due to triangular load was greater by 20% and 70% than results from uniformly distributed vertical load and horizontal load respectively. Morever, there was an increase of more than 60% in tensile strain at the bottom of the asphalt layer, Ex, and compressive strain, Ez, at the top of subgrade layer for triangular load as compared to uniformly distributed load. Planned future publications will use results from SIM measurements and look at practical implications of this type of non-uniform loading on performance of different types of pavement structures.