Small Strain Stiffness of Sand under Different Isotropic and Anisotropic Stress Paths Measured by Seismic Wave-Based Testing Techniques

This paper presents a study of a uniform dry sand compacted by the pluviation method and submitted to different isotropic and anisotropic stress paths. The stress states were performed in two distinct triaxial cells using specimens of 100 mm and 150 mm diameter in order to assess also the scale-effects. The small strain stiffness for each stress state was evaluated in both triaxial cells by bender elements which were assembled vertically and horizontally for the comparison of the shear wave velocity in the two directions. In the specimens of 100mm, additionally to the bender elements in the vertical direction, accelerometers were used for the improvement of the results accuracy. All tests results were analysed in order to assess the initial fabric (inherent) anisotropy and the induced anisotropy by the different anisotropic stress paths.