Plastic strain rate in granular materials as a function of stress history: a probabilistic approach for the PBD model

Abstract

ABSTRACT The permanent deformation of granular materials is an important indicator in making decisions associated with the traffic of superheavy vehicles on pavements. The PBD model, a recently developed mechanistic-empirical model, analyzes the effect of superheavy load vehicles using the plastic strain rate as an indicator. The plastic strain rates of materials subjected to repeated cyclic stresses are defined by two states: (1) the post-compaction phase and (2) the shakedown state, with a probable range of permanent deformation being defined from each of these states. This paper explores the limits of applicability of the PBD model at different times in the stress history of granular materials. An accelerated pavement test with typical pavement structures from Quebec (Canada) is used as a reference. The changes in the plastic strain rate to variables related to the stress history in the granular material were studied, and a probabilistic relationship is proposed to improve the analytical predictions of the PBD model.