Measurement of Shear Waves in Laboratory Specimens by Means of Piezoelectric Transducers

The use of piezoelectric ceramics to measure shear wave velocity in laboratory soil specimens is discussed. The experimental technique and interpretative methodology are described. Both bender and flat-plate ceramic elements were employed, and each performed well. Interpretation of the shear waveforms generated with each transducer improved as the number of wavelengths between the source and receiver increased, with four or five wavelengths being optimum. Shear wave velocities measured using both types of transducers compared closely with the results of a parallel program performed with the torsional resonant column. Based on this work, flat-plate shear transducers show significant potential for future laboratory use because of their robustness and noninvasive nature.