Abstract: The microslip model is a new approach to the mechanism of strain localization in sand deformation. As an extension of the previous study Mechanics of Materials 8 (1989)89-102 , the paper presents a mathematical formulation of the microslip model with boundary constraints, based on the method of pseudo-tractions and the boundary element methol. Special attention is given to the effect of boundaries on strain localization. Some interesting aspects of the problem, such as the dependence of the deformation ch...