Numerical modelling of nonlinear response of soil. Part 2: Strain localization investigation on sand

In this contribution, numerical investigations of strain localization have been performed on 3D dense saturated sand specimens subjected to triaxial loading conditions. The importance of the presence of fluid on the formation and evolution of strain localization are identified by several analyses. The role of the fluid components on strain localization is addressed computationally. The important influencing factors, such as soil permeability; water suction; draining conditions and specimen geometry on strain localization development and the formation of localization pattern are presented in detail. Mesh sensitivity issues have been studied by means of both, a one-dimensional wet soil bar subjected to dynamic compression load and, a 3D saturated specimen subjected to triaxial loads. It has been shown that, in a multiphase material, the fluid (water) phase plays indeed an important role in strain localization. The formation and evolution of strain localization are influenced both by the material behaviour of the media and the interaction between fluid and solid components. A companion paper focuses on the development of the constitutive model to simulate the soil response in the elastoplastic range has been addressed, and a general procedure has been developed for determination of the material parameters of the constitutive model.