68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

IMPROVEMENT OF THE PIEZO-ELECTRIC RING ACTUATOR TECHNIQUE (P-RAT) USING 3D NUMERICAL SIMULATIONS

Session: Laboratory Testing III / Essais en laboratoire III

Ahmed Mhenni, Université de Sherbrooke (Canada)
Mourad Karray, Université de Sherbrooke (Canada)

Shear wave velocity of soil is commonly measured in the laboratory using piezoelectric elements such the bender elements (BE). These techniques, however, are associated with several difficulties including the mixed radiation of both primary and shear waves, near-field effects, boundary effects, and uncertain detection of first arrivals. A new technique, piezoelectric ring-actuator technique (P-RAT) has been developed in the geotechnical laboratory at the Université de Sherbrooke to minimize/eliminate the difficulties associated with other techniques, in particular, the penetrating of the used sensors into the tested specimens that may be inescapable in BE technique. This paper presents a brief description of the P-RAT technique as well as the results of 3D numerical simulations conducted using the computer code, COMSOL in order to study the interaction between the P-RAT components and the tested sample (soil or solid). This study demonstrate the effectiveness of the P-RAT technique andshows that the 3D simulations can be used in order to improve the reliability and/or the performance of the P-RAT to expand its applicability in the field of civil engineering.