Soil Ring Shear Test Apparatus

Cutting box:
The core component is a circular (concentric) structure, divided into upper and lower parts. The inner ring fixes the soil sample, and the outer ring rotates to apply shear force, achieving infinite shear displacement (avoiding the displacement limitation of conventional direct shear instruments).
The sample size is usually 10-20 cm in outer diameter, 6-10 cm in inner diameter, and 1-5 cm in height.

Loading system:
Vertical load: Apply constant normal stress through air pressure, hydraulic pressure, or weights to simulate soil burial depth pressure.
Shear load: The motor drives the outer ring to rotate at a constant speed, and the torque sensor records the shear force.

Measurement system:
Displacement sensor: monitors shear displacement.
Pore water pressure sensor (if saturated soil): measures changes in pore water pressure under drainage conditions.
Data acquisition system: Real time recording of parameters such as shear stress, displacement, and volume changes.

Control system:
Adjust the shear rate (usually 0.001-10 mm/min), normal stress, and experimental mode (drained/undrained).

soil Ring Shear Tester Key parameter
Shear strength parameters: residual internal friction angle (にₑ), cohesion (c ₑ).
Stress strain curve: reflects the softening process of soil from peak strength to residual strength.
Volume change: dilatancy or compressibility (monitored by changes in sample height).