A failure criterion for cross-anisotropic soils considering microstructure

Strength anisotropy is an important soil behavior which is closely related to the microstructural characteristics in soil. Proper consideration of the microscopic properties of a soil is key to accurate description of its strength anisotropy. This paper presents a failure criterion for cross-anisotropic soils based on the Spatially Mobilized Plane (SMP) criterion. In the new criterion, the shear-normal stress ratio defined in the SMP is related to the relative orientation of the loading direction with respect to the axes of material anisotropy through a microstructure-based tensor. The formulation includes only two parameters which can be easily calibrated by conventional triaixal tests. By comparison with tests data, the criterion is shown to offer good characterization of the strength anisotropy for a variety of geomaterials with cross-anisotropy