by Alec McGillivray1, Thomas Casey1, Paul W. Mayne2, and James A. Schneider3
Keywords: cyclic loading, cone penetration test, earthquakes, in-situ testing, liquefaction, piezocone, porewater pressures, vibrocone
ABSTRACT
An electric downhole vibrocone has been designed for the site-specific evaluation of soil liquefaction susceptibility in high seismicity regions. The device induces localized cyclic pore pressures while concurrently measuring dynamic tip and friction resistances. The latest design couples a dual-element penetrometer with a piezo-actuator shaker. This vibrocone offers a number of advantages over its predecessors including downhole vertical oscillation, adjustable dynamic force and frequency of excitation, and the simultaneous measurement of porewater pressures at multiple positions.