DEFORMATION OF WATER-SATURATED SAND .2. EFFECT OF PORE-WATER FLOW ANDSHEAR BANDING

Previous undrained biaxial experiments on water-saturated sand are ana lysed in relation to shear banding and linear stability under locally drained and globally undrained conditions, The regularization of the u nderlying mathematically ill-posed initial value problem in the small strain regime of deviator softening is achieved through viscous singul ar perturbation of the flow theory of plasticity, In the regime of lar ge strains the problem is regularized by means of a non-coaxial regula r perturbation combined with a second grade singular perturbation of t he flow theory of plasticity. The occurrence of shear bands under glob ally undrained conditions is critically discussed.