Effect of median particle size on S- wave velocity and frequency domain responses of granular materials

For assemblies of spherical particles with Hertzian contacts, the stress wave velocities should not depend on particle size. However, a link between particle size and stress wave velocity has been reported in laboratory experiments. In this study, to identify the reasons for the discrepancies, shear wave velocity measurements were performed using planar piezoelectric transducers on four different sizes of alkaline glass beads and natural silica sands. The experimental results indicate that shear wave velocities are independent of the median particle size. However, the maximum frequency that can propagate through a granular assembly reduces with increasing median particle size.