Electrical Vane Shear Testing
ESTIMATION OF UNDRAINED SHEAR STRENGTH IN CLAY AND MINE TAILINGS
Electrical vane shear testing is mainly used to estimate undrained shear strength and remoulded (residual) shear strength. It is frequently employed along with other tools such CPT, CPTu, SCPTu and DMT.
The system mainly consists of a vane that is rotated through a software-controlled motor. Measurements with a high-precision torque sensor are used to derive shear strength values at depths of interest.
Standard rates of rotation yield accurate results at saturated, fine-textured materials such as clays. Certain silty soils and tailings may be kept undrained during the test by increasing the rate of rotation. However, more permeable materials cannot be investigated with shear vanes since partial or total drainage would occur.
Samples can be rapidly collected using direct push technology in adjacent locations upon request.
MAJOR BENEFITS OF LEGION DRILLING’S ELECTRICAL VANE SHEAR TESTER
Fully software controlled. More precise torque and rate of rotation than manual systems.
Vane rods protected with a sheath to avoid friction that would affect the results.
Rotation speed adjustable between 0.1 and 20 degrees per second.
Nominal torque of 100 Nm.
Real-time data visualisation.
Standardised method and third-party calibrated equipment.