A precise evaluation of shear wave velocity, V s, is a crucial issue in the design of foundations subjected to dynamic loading, liquefaction evaluation and soil improvement control. Laboratory techniques such as resonant column (RC) and bender element (BE) have been developed over the years to measure V s. At low strain (γ 10-3), techniques based on piezoelectric elements (eg BE) can be considered superior to RC since they can be used in conventional geotechnical devices (eg triaxial, oedometer, DSS, etc.). However ...