Hollow Cylinder
The Hollow Cylinder Apparatus (HCA) allows direct application of shear stress or shear strain to a soil specimen of a hollow ring-shaped cross-section (Buchheister, 2009). Manufactured by Wille Geotechnik, the apparatus is equipped with 2 hydraulic units, offering 2 possible regulations: displacement/axial force and/or rotation/torsion. The HCA is equipped with three pressure-volume controllers to independently control the outer and inner cell pressure, and the pore water pressure. Two different specimen sizes can be tested, with outer diameter 100 and 150 mm. The apparatus can apply a maximum force of 50 kN and a maximum torque of 200 Nm, both with a maximum axial frequency of 10 Hz. Naturally, the hydraulic press can also be used to perform static or dynamic triaxial tests.
The technical specifications of the HCA are summarized as follows:
- Large specimen: 150 mm (75 mm) outer (inner) diameter, 300 mm height
- Small specimen: 100 mm (50 mm) outer (inner) diameter, 200 mm height
- Maximum axial force: 50 kN
- Maximum torque: 200 Nm
- Maximum axial displacement: 100 mm
- Maximum axial and torsional frequency: 10 Hz
- Maximum cell pressure: 1000 kPa
