Softening response under undrained compression following anisotropic consolidation

Experimental evidence has indicated that clay exhibits strain-softening response under undrained compression following anisotropic consolidation. The purpose of this work was to propose a modeling method under critical state theory of soil mechanics. Based on experimental data on different types of clay, a simple double-surface model was developed considering explicitly the location of critical state by incorporating the density state into constitutive equations. The model was then used to simulate undrained triaxial compression tests performed on isotropically and anisotropically consolidated samples with different stress ratios. The predictions were compared with experimental results. All simulations demonstrate that the proposed approach is capable of describing the drained and undrained compression behaviors following isotropic and anisotropic consolidations. © 2013 Central South University Press and Springer-Verlag Berlin Heidelberg.