ANISOTROPIC DEFORMATION CHARACTERISTICS OF SAND UNDER THREE DIMENSIONAL STRESS CONDITIONS

ABSTRACT A true triaxial shear test box equipped with six rubber pressure bags was constructed to test cubical specimens of sand with a dimension of 100 mm × 100 mm × 100 mm. A series of drained tests was carried out on loose sand specimens prepared by depositing the sand under water. The tests employed different radial stress paths in which the major, intermediate and minor principal stresses were oriented independent of the direction of the specimen sedimentation. The test results indicated that when the shear stress was small the deformation of the specimen thus prepared was highly anisotropic because of the inherent anisotropy of the specimen, but when the shear stress became large enough to produce failure the effects of inherent anisotropy disappeared. A number of tests were also carried out on specimens rotated by 90° about the horizontal axis after the specimens had been prepared by deposition.