Description
Hollow Core – Computer-controlled Cyclic Torsional Shear Test Apparatus used to investigate soil behavior under static or cyclic loading conditions.

Features
Conventional triaxial features (back pressure saturation, consolidation, and axial shearing stages under drained and undrained conditions).
Capability to control all three principal stresses acting on the soil (e.g., σ1, σ2, σ3).
Option to perform torsional monotonic shear to investigate soil static shear strength.
Option to perform torsional cyclic shear to investigate cyclic strength and liquefaction.
Option to measure post-liquefaction shear strength.

What Can Be Performed?
Torsional shear at frequencies ranging from 0.0125 Hz to 2 Hz at appropriate strain levels.
Strain/stress-controlled user-defined irregular loading/strain tests.
Consolidation under isotropic and anisotropic conditions.
Triaxial or stress path shear testing after torsional shear.

Data Acquisition
8-channel FastDAQ data logger with SD card backup data recording, using the free GeoGram data acquisition software.

Control
Stress- and strain-controlled testing can be performed using the GeoAnts Controller software.

Safety Features
Upper and lower limit switches to stop excessive actuator movement.
Left and right limit switch mechanism to stop excessive actuator movement.
Built-in software safety shutdown when sensors reach maximum limits.
External emergency stop, overcurrent, and overtemperature shutdown protection.

Technical Specifications

Sample Outer Diameter 150 mm
Sample Inner Diameter     100 mm
Chamber (Cell Capacity)      Up to 1.7 MPa
Load Frame Capacity      50 kN
Back Pressure Capacity     Up to 1 MPa
Axial Load Capacity          Up to 10 kN
Torque Capacity             300 Nm
Loading Frequency           Up to 2 Hz for the torsional cyclic shear phase

Monotonic Test Features Consolidated, unconsolidated, drained, undrained triaxial and     strain-controlled tests up to 10% axial strain and up to 30% shear strain as standard.

Cyclic Test Features Consolidated, unconsolidated, drained, undrained triaxial tests and, as standard, cyclic axial strain up to 10% and cyclic shear stress stress-path tests up to 30%.

Customization All of the above features can be adjusted according to your   specific requirements.