The GCTS Residual Ring Shear Testing System (SRS-150) is a fully automatic, electro-pneumatic, servo-controlled testing system used for determining the drained residual strength of continuously sheared soils. The SRS-150 ring shear apparatus was developed using the Harmonic Drive™ motor technology for a true continuous shearing rate without inherent backlash found in gear assemblies of other ring shear devices.
The Harmonic Drive ™ shearing actuator allows for a large range of shearing rates at very high resolutions and a large torque capacity. The SRS-150 is capable of applying shearing rates ranging from 0.001 to 360 degrees per minute continuously without backlash for replication of true in-situ strain rates during failure. It is fitted with an electrical slip ring, which allows for unlimited continuous specimen shearing through multiple full rotations to measure the full residual strength.
The SRS-150 is capable of performing “multi-stage” tests where a sample is consolidated at a given pressure, sheared to its residual strength, then consolidated to a new pressure and sheared again. This procedure allows for determination of the failure envelope using a single specimen.
The device accepts 150 mm OD and 100 mm ID samples for testing granular materials. The system components are conveniently placed inside the rolling cart for mobility and ease of specimen preparation.
ASTM D6467 – Standard Test Method for Torsional Ring Shear Test to Determine Drained Residual Shear Strength of Cohesive Soils