Testing of soil or ground samples using a wooden pile driver apparatus, whereby striking frequency and strength are readily adjusted by varying a return spring force and the piston stroke

摘要

Method for operating a pile driver for a ground sample probe. The pile driver comprises a hollow cylinder (16) with open ends covered by covers (17, 18) and a piston (20) contained within the cylinder. The piston is raised within the cylinder using compressed air until a spring pressure balances the lifting force. At this point the pressure is released so that the piston drops against an end surface (23). Adjustment of the spring force and piston stroke can be used to change the striking force and frequency.