Shear Wave Propagation in Granular Media: Effects of Particle Size and Sensor Dimensions

This study investigates the effects of particle characteristics and bender element dimensions on shear wave propagation in granular media under K0 loading conditions. Fourteen granular specimens are tested using five bender elements of varying lengths and widths. A modified oedometer cell is employed to measure the shear wave characteristics with an increase in the vertical stress. Experimental results show that the shear wave velocity increases with the vertical stress, with the rate of increase varying depending on the size and shape of the particles. The resonant frequency and wavelength are governed more by intrinsic particle properties, such as the particle shape and packing state, than by the geometry of the bender elements. A minimum wavelength ratio of 1.6 is confirmed to be a reliable criterion for minimizing near-field effects. The shear wave energy exhibits a complex dependency on the particle characteristics and bender element geometry, with distinct trends observed between glass bead and silica sand specimens. Further, the α and β parameters, which characterize the velocity−stress relationship, vary with the particle shape and mean diameter, while exhibiting minimal sensitivity to the dimensions of the bender elements. Therefore, this study suggests that selecting an appropriate configuration of particle properties and transducer dimensions is essential to obtain accurate shear wave measurements in granular media.