In-Place Measurement of Deep Sea Soil Shear Strength
SourceA vane shear device was developed for in-place measurement of the undrained strength of clays in the marine environment. It was designed to operate at a water depth of 4.6 km (15,000 ft) and to penetrate nearly 3 m (10 ft) below the mudline in steps of about 0.3 m (1 ft). The device contained its own power supply. Data were wire telemetered to the ship for recording and analysis. Experiments in several locations in the Atlantic Ocean and the Gulf of Mexico demonstrated the capability of the apparatus. The shear strength measured in place generally exceeded the strengths measured on soil samples collected from shallow water, where the sedimentation rate was relatively rapid. There was little difference between shear strength measured in place and on cores from the Gulf of Mexico abyssal plain site, where the sedimentation rate was slow.