EFFECTS OF SEDIMENTARY DIRECTION AND PARTICLE SIZE COMPOSITION ON MECHANICAL BEHAVIORS OF SAND¹⁾

Using the pseudo cohesive force formed by the capillary effect of the sand to prepare samples with different sedimentary directions, a series of the triaxial consolidation drainage shear tests are performed to study the influence of the granulometric composition on the mechanical properties of the initial anisotropic sand. The relationship among the granulometric composition, the sedimentary direction, the strength characteristics and the volume change is analyzed. The results show that the formation of the shear band is affected by the particle size distribution, which is the cause of the sharp drop stage in the stress-strain relationship. The sedimentation direction has an effect on the deviatoric stress peak strength of the coarse sand and the fine sand, and the effect on the residual strength is limited by the particle size distribution. When the sedimentary direction is close to the failure surface of the sample, the strength of the sample is low, the dilatancy deformation of the sample is small and it is easier to be damaged, and the granulometric composition has a more significant influence on the triaxial shear mechanical behavior of the sand.