To study the cross-anisotropy of aeolian sand across a wide range of stress levels, the anisotropic specimen is prepared and sheared along three sectors of octahedral planes in a true triaxial apparatus. Test results show anisotropic deformation when responding to different orientations of principal stress, with the highest dilatancy when the effective major principal stress \(\sigma^{\prime}_{1}\) is vertical to the bedding plane (sector I), and apparent contraction when parallel (sectors II and III). The effect of inherent anisotropy on strength is affected by the mean effective principal stress p′. As the rise of p′, the peak stress is largest when \(\sigma^{\prime}_{1}\) is vertical to the bedding plane, and the inherent anisotropy determines the decreasing trend of peak stress with stress Lode angle θσ from − 30° to 150°. However, the peak stress in sectors II and III is larger than the Mohr–Coulomb criterion at low-stress levels, indicating an effect of stress-induced anisotropy, especially at p′ = 50 kPa. At special intermediate principal stress coefficients b values (0.2, 0.4), the triggering of the shear band also produces unsmooth failure surfaces. The anisotropic behavior under different stress levels is analyzed based on the principal strain responses, and the evolution of frictional properties in all sectors reveals the anisotropic failure of aeolian sand.
