Undrained Response of Granular Soil Involving Localized Deformation

In this paper an attempt is made to provide a macroscopic description of undrained deformation, in saturated granular materials, in the presence of a shear band. First, the case when both constituents (i.e., the intact and shear band material) respond in an undrained manner is considered. Subsequently, the problem is reformulated by allowing for an exchange of water (partial drainage) in constituents due to a rapid dissipation of the excess pore pressure gradient. The formulation is applied to analyze the plane strain undrained deformation of a dense sand. The classical bifurcation analysis is used to predict the onset of localized deformation. The results of numerical simulations, both prior to and past the localization, are compared with the available experimental data.