Undrained shear strength for K₀ overconsolidated clays

The unified equation of the undrained shear strengths is deduced by combining K₀ overconsolidated clay model, the function of rotating angle, the critical state conditions of the clay and the transformed stress tensors based on SMP criterion. The stress Lode angle θ and the rotating angle ω under the triaxial compression and extension condition, and under the plane strain compression condition are applied to develop the corresponding undrained shear strength equations, respectively. The theoretical results for K₀ overconsolidated clays are in good agreement with the experimental data.