Three-dimensional strength criterion for layered-anisotropic cohesionless soils

By neglecting the cohesion term and using an elliptical shape function, a 3D Mohr-Coulomb strength criterion was proposed to describe the strength of cohesionless soils. The proposed criterion predicts the dependency of the peak friction angle on the intermediate principal stress ratio well. According to the direction of deposition and the major principal stress, a term, which includes a layered-anisotropic parameter representing the ratio of soil strength perpendicular and parallel to the sediment, was added into the shape function, then, a simplified strength criterion for layered-anisotropic cohesionless soils is proposed. The suitability of the criterion was tested by studying the influence of layered-anisotropic parameter on the shape of deviatoric plane and the relationship between the peak friction angle and the intermediate principal stress ratio. By comparing with the experimental results of true triaxial tests on sands, the proposed strength criterion was validated to predict the strength of layered-anisotropic soils.