Development of an Anisotropic Nonlinear Strength Criterion for Geomaterials Based on SMP Criterion

Based on the strength criterion of the nonlinear spatially mobilized plane (SMP), an anisotropic nonlinear strength criterion is presented to accurately describe the strength anisotropy of geomaterial. An anisotropic variable with the friction coefficient of the nonlinear SMP strength criterion is introduced to account for the influence of anisotropy. A new criterion is illustrated on both the meridional and octahedral planes, which greatly simplifies the methods of capturing the anisotropy of geomaterials under various stress paths. In addition, only traditional triaxial tests are used to determine the model parameters of the criterion. The test results from sand, clay, and rock for the complex conditions of the true triaxial test and torsional shear test show that the anisotropic strength criterion can be utilized for various geotechnical materials. Compared with the prediction of test results mentioned in the relevant literature, the new criterion proposed in this paper can predict the anisotropic strength of various geotechnical materials.