Strength of Cross anisotropic Soils Considering Influence of Principal Stress Direction

Abstract:

According to the relationship between the material fabric and axis of major principal stress, the elliptic shape function was revised by adding a cross anisotropic term, and then a 3D cross anisotropic failure criterion was proposed based on the Mohr Coulomb criterion. The formula for calculating the peak stress ratio under different intermediate principal stress ratio condition was deduced, then the varying characteristics of peak friction angle with the intermediate principal stress ratio and the angle of major principal stress direction relative to material fabric were also obtained. A comparative study of a series of triaxial tests with different sample sedimentation angles and hollow cylinder tests shows that the predicted friction angle agrees well with the experimental results.

Key words:soil strength; principal stress direction; cross anisotropy; material fabric