Stress-strain states in sandy materials

Thesis compares dynamic shear modulus of soil in different stress states obtained by tests in hollow cylinder apparatus. The first part of thesis represents theoretical background of cyclic torsional shear test on hollow cylindrical specimens in sense of stresses and strains which appear in hollow cylindrical specimens during testing. This part includes also conclusions of tests mentioned in the literature. Next part is a study of a procedure for preparation of sandy specimens and testing procedure according to the Japanese standards for determination of deformation properties of soil with hollow cylinder apparatus (JGS 0543-2000). After literature review in first part of thesis experimental part follows in which cyclic torsional shear tests on hollow cylindrical specimens were done with purpose to determine an impact of anisotropic consolidation on dynamic shear modulus of soil. Six tests were made in two different sandy materials with different initial effective circumferential stresses. All tests were in first part deformation controlled like it is prescribed in mentioned Japanese standard. The assumption of an impact of anisotropic consolidation on the shear stiffness of soil planed to be confirmed. The second part of tests were stress controlled test in few steps to see what is the impact of different direction (shear, axial, shear and axial) of loading up on the response of soil. The specimens of one-granular sand were prepared after dry deposition method, while samples of sandy silt were prepared after sedimentation method