Development of a speargun projectile penetrometer in soil

• Published in: Canadian geotechnical journal Vol. 61; no. 11; pp. 2588 - 2592
• Main Authors: Rong, Junlin, Nazem, Majidreza, Chow, Shiao Huey, Zhou, Annan, Moridpour, Sara
• Format: Journal Article
• Language: English
• Published: Ottawa Canadian Science Publishing NRC Research Press 01-11-2024
• Subjects: Kinetic energy; Laboratory tests; Offshore; Penetration depth; Penetrometers; Projectiles; Soil investigations; Soil testing; Vertical penetration
• ISSN: 0008-3674; 1208-6010
• DOI: 10.1139/cgj-2023-0732

This study investigates the applicability of a speargun projectile penetrometer (SPP) for offshore site investigation purposes using experimental testing. The SPP can shoot penetrometers using an elastic/pneumatic force. The speargun is easy to handle, can generate significant kinetic energy, and requires a single operator to perform the test. A laboratory test platform was utilised to hold the SPP and ensure vertical launch, while a laser displacement sensor was employed to monitor the penetration depth and record the corresponding time history. The result demonstrated that the speargun-launched method achieves significantly higher embedment depth compared to an equivalent free-falling penetrometer. In particular, the new method produces sufficiently deep penetration in dense sand, thus overcoming the typical penetrometer tilting issue caused by shallow penetration. These findings provide a preliminary insight into the SPP, allowing for exploration beyond the boundaries of traditional penetrometers in laboratory testing and offshore site investigation.