INFLUENCE OF STATIC SHEAR STRESS ON THE CYCLIC VOLUME CHANGE BEHAVIOR OF OTTAWA SAND.

The stress-strain relationship and volume change characteristics of Ottawa sand has been investigated in drained simple shear test for varying amplitudes of cyclic shear and static shear stress. Results show that the cumulated shear and volume strains increase with increase in the cyclic stress ratio and static shear stress, however, after the first cycle the magnitude of the volume strains are essentially independent of the amplitude of the static shear stress. It is further shown that within a cycle the larger the shear strain the larger the volume strain which results and that the primary cyclic volume strains occur within the first 10 cycles after which densification hardening occurs with little significant strain developing after 30 cycles.