Simulation of cyclic triaxial tests with constant and variable confining pressure using empirical equations

Abstract

Abstract
In the world the most used equations in order to predict deformations in unbound granular materials (UGM) of flexible pavement structures are empirical. Many researchís projects have been performed in this area, however the discussion if these equations are reliable have not finished yet. Initially, the paper presents the evolution of some empirical equations developed in order to try to predict the permanent strain accumulation that undergo unbound granular materials (UGM) in cyclic triaxial tests with constant and variable confining pressure (CCP and VCP respectively). Based in the analysis of such equations, the most used in the world were chosen in order to simulate the behavior that underwent a UGM in CCP and VCP tests. The simulations performed, shown that the most part of the empirical equations used to predict the permanent strain accumulation in UGMís can not reproduce the behavior of these materials in CCP and VCP tests. Additionally, the parameters used in such equations are not constants of the material.