Evaluation of the effect of anisotropic consolidation and principle stress rotation on underained behavior of silty sands

The dependence of undrained behavior of silty sand on initial state of stress and direction of principal stresses with respect to vertical () is assessed under generalized loading paths using hollow cylinder apparatus. During applying shear load, value of intermediate principal stress parameter (b) is held constant and  value is increased from zero to the aimed value and held constant. Specimens are consolidated, both, isotropically and anisotropically to evaluate the eect anisotropic consolidation on the behavior of these soils. The wet tamping method was selected to prepare specimen. Shear loading was carried out under strain-controlled condition to capture post-peak strain-softening response. The results of this study reveal that the principal stress direction and initial anisotropy in stress condition have considerable eects on the behavior of silty sands. By increasing , susceptibility of silty sand to instability increases. In addition, increase in silt content of silty sand mixtures presents higher tendency to ow compared to pure sand. For specimens with high silt content, it is observed that stress-strain response has a sudden reduction in shear strength after a peak. This study reveals that shear strength and steady state friction angle of the silty sands are aected by  and the amount of nes present in the sand.