Effect of fabric and initial stresses on the anisotropic behavior of sand

This study investigates the anisotropy in the stress-strain-strength behavior of Firoozkuh sand، focusing on the e ect of the initial stress state and soil fabric. The experiments are performed using a hollow cylinder apparatus. Di erent initial conditions are considered by maintaining the principal stress ratio (i. e. Rc = 01 c=03c) and the inclination of initial principal stress (i. e. c) during consolidation. The specimens are prepared using two di erent methods to assess the influence of soil fabric. The direction of increments of principal stresses، ، is controlled to remain constant during the test. Generally، the results showed a decrease in the shear strength of sand by increasing . In specimens consolidated under the inclined anisotropic stresses، the trend of shear strength variation versus  di ered and depended on c. The vertical consolidated sands (Rc = 2، c = 0) were found to be highly in uenced by . The anisotropic behavior of medium dense sands was observed to be strongly dependent on the initial stress state. The results showed that the stress-strain behavior of specimens prepared by the wet tamping method is strongly in uenced by . The e ect of soil fabric and initial stress state on the shear modulus was more noticeable than that on the shear strength of sand.