CMS-9622670 The deformation of soils in the field and laboratory are commonly observed to concentrate in shear bands formed during failure by strain localization. While this mechanism is widely appreciated by geotechnical engineers, it remains difficult to account for this in the numerical solutions. This research is the analytical/computational component of a collaborative research project which includes the University of Southern California (USC), Case Western Reserve University (CWRU), and two French engineering institutions - the Institute Mecanique de Grenoble (IMG) and the Ecole Centrale de Paris (ECP). The research will build on the experimental investigations at CWRU, IMG, and ECP to develop the analytical/computational framework for strain localization based on finite element implementation of gradient-dependent plasticity, and including account of the diffusion of pore water during undrained tests. The experimental and analytical program will lead to a better understanding of the phenomenon of bifurcation and localization, and to analytical methods for analyzing strain localization not only in laboratory specimens, but also in practical boundary value problems in geotechnical engineering. ***