The Development of the Torpedo-Piezocone

The paper describes the development of a soil investigation equipment, consisted of a piezocone installed at the tip of a torpedo-pile. The new equipment, named torpedo-piezocone, is able to measure cone resistance (q_c), sleeve friction (f_s), pore-pressure at the cone face (u₁) and cone shoulder (u₂) as well as cone temperature during free-fall and some time after final stop. Velocity, as well as displacement (depth) are obtained from accelerometer data, as in the case of the torpedo-pile. The various steps to develop the equipment are presented, from the requirements of the transducers until the calibration procedures in the laboratory. The first tests performed onshore are also presented. In general, very good results have been obtained.