Strength criteria and slipping planes of anisotropic sand considering direction of major principal stress

The effect of directions of the principal stress on the deformation and strength of sand is due to the anisotropy of soils. The shear strength on a certain plane of the cross-isotropic sand is larger when the angle between this plane and the bedding plane is larger. Assuming that the intrinsic anisotropy strength of sand is closely related to the anisotropy parameter of the plane, the peak strength of anisotropic soils is presented. As the shear-normal stress ratio of each potential slipping plane of the SMP criterion is the same, the shear strength and position of the slipping plane are determined by the potential slipping plane with the lowest shear strength. On this basis, an anisotropic strength criterion is proposed by considering the relationship among the principal stress axis, the slipping plane and the bedding plane. A series of shear tests with fixed direction of the major principal stress are carried out using Fujian standard sand in order to systematically observe the slipping plane of the specimens. Comparison between the predicted data and the measured results indicates that the anisotropic model can well reflect the strength and the position of the slipping plane of the anisotropic soils.