The research applies recent solid mechanics advances to shear localization behavior and develops a verified approach to predict the stability of geo-materials such as rock and concrete structures. The main goal of this work is to understand the physical process of strain localization in geo-materials and provide a theoretical framework for the extrapolation of laboratory observation to applications. Comprehensive studies are conducted on shear localization in rocks and other geo-materials that exhibit sensitivity of inelastic deformation and inelastic volume change. The studies combine theoretical analyses with computational and experimental work. Improved constitutive relations for multiaxial and inelastic deformation will be formulated and a framework will be developed for the use of constitutive models in numerical codes. Specifically, shear rupture in pressure-sensitive and inelastically compressible solids will be investigated based on models involving bifurcation from homogeneous deformation. The investigations of localization will then be used with experimental observations and numerical calculations to study the performance of inelastic constitutive relations for multiaxial deformation of geo-structures.
