An Anisotropic Failure Criterion for Cross-anisotropic Soils

Abstract

Strength anisotropy is an important feature closely related to soil microstructure characteristics. A new anisotropic failure criterion, extended from the Ogawa failure criterion, was developed to describe the strength anisotropy of cross-anisotropic soils. Nonlinearization of the failure curves of the Ogawa failure criterion was introduced to account for the nonlinear failure of cross-anisotropic soils in the meridian plane. Meanwhile, an anisotropic strength function based on fabric tensor was theoretically proposed to modify the failure strength under different loading directions and depositional angles. The evolution of the new anisotropic failure criterion in the deviatoric plane was investigated through a series of parametric studies. All of the undetermined parameters in the new criterion can be readily determined in laboratory tests. Compared with experimental results on several types of soils, the new anisotropic failure criterion showed good performance in strength prediction in the deviatoric plane, as well as predicting the peak friction angle. Finally, a linear theoretical relationship on construction of the anisotropic strength function was also elucidated and discussed. The new anisotropic failure criterion proposed in this paper can effectively predict the strength anisotropy of cross-anisotropic soils under different loading directions and depositional angles.