Abstract
The stress-strain behavior of a granular material is highly complicated relative to that of a cohesive soil. Due to the frictional nature of the material, a plasticity framework based on non-associated flow rule is generally considered to be most suitable for modeling its constitutive behavior. By employing two surfaces, it is shown in this paper that a plasticity model based on an associated flow rule provides a satisfactory means of simulating, under a monotonic loading, the stress-strain behavior of dense and loose sands under triaxial undrained and drained loading conditions.
