A sophisticated T-bar mini-penetrometer for exclusive in-field seabed strength profiling of box core samples is now available from environmental monitoring experts Ocean Scientific International Ltd (OSIL).
The T-bar penetrometer measures the resistance of sediment to continuous penetration at a slow steady rate using a cylindrical rod (T-bar) at the end of a perpendicular push rod or thruster and, uniquely, is small enough to fit on to the top of a box corer sample box immediately on its recovery on-deck to allow for on-site sampling on the back of the vessel.
Using axial load, dual axis tilt and friction sleeve sensors the system can provide a real time display that records penetration length, penetration resistance and inclination from the vertical for every millimetre of penetration at 2cm/s, and also stores the data for later analysis. The system can be fitted with a 25cm2 T-bar, 50cm2 T-bar, or 50cm2 Ball, depending on soil conditions.
Penetrometer testing is used to characterise the undrained shear strength and residual shear strength profiles of seabed soils, which provides valuable data for the positioning and design of a variety of subsea structures.