A novel transversely isotropic strength criterion for soils based on a mobilised plane approach Available to Purchase

The peak shear strength rules of transversely isotropic soils are stress state dependent and dependent on relative orientation between bedding plane and principal stress. Accordingly, the shear strength of transversely isotropic soils exhibits two primary characteristics: (a) the strength curve on the deviatoric plane is asymmetrical with respect to three principal stress axes; (b) the shear strength changes with the direction angle of the bedding plane when the intermediate principal stress coefficient is a constant. In this paper, the mobilised plane is introduced and used to reveal the failure mechanism of soils. By projecting the microstructure tensor of transversely isotropic soils onto the normal of the mobilised plane, the directionality of the transversely isotropic soils is introduced into the friction rules on the mobilised plane, and a transversely isotropic strength parameter is proposed. The proposed strength parameter can extend isotropic strength criteria into transversely isotropic strength criteria. This mobilised plane approach is used to establish a novel transversely isotropic non-linear unified strength criterion (TI-NUSC). The difficulty in establishing a unified description of the asymmetrical strength curve and its evolution with direction angle is overcome by the established criterion. Comparisons between available test results and the TI-NUSC show that the TI-NUSC can successfully describe these two primary peak strength characteristics.