Rock Direct Shear Testing System
RDS-200 Direct Shear Testing System

The GCTS RDS-200 Direct Shear System for Rocks is a simple and inexpensive apparatus for testing a variety of rock specimen configurations. This automated system includes advanced software to make the testing experience much easier for the user. GCTS also offers a more affordable manual system.


  • Closed loop servo control of double acting (push/pull) 100 kN (10 ton) shear load actuator with 25 mm stroke and 50 kN (5 ton) normal load actuator with 25 mm stroke.
  • Normal load stiff reaction frame mounted on sliding bearings to minimize horizontal friction while keeping the normal load vertical throughout the full shear displacement.
  • 150 mm (6") inside diameter sample rings for specimens up to 150 mm high.
  • Software for automatic performance of direct shear tests with constant normal stress or constant normal stiffness.
  • Real-time graphical display of test progress.
  • Other load capacities and specimen size dimensions are available, including large-scale test systems for shear loads of up to 1,000 kN (100 ton) and specimen sizes up to 300 mm diameter or side.



Related Documents


Day, J.J., Diederichs, M.S., Hutchinson, D.J., 2017. New direct shear testing protocols and analyses for fractures and healed intrablock rockmass discontinuities. Eng. Geol. 229, 53-72.

The GCTS Rock Direct Shear System is a simple and inexpensive device for testing a wide range of rock specimen configurations. Cylindrical cores, cubes, prisms, and rock fragments can be used to determine the shear strength.


This system features electro-hydraulic closed-loop digital servo control of the shear and normal loads for test automation. The included software program accepts inputs from the normal load sensor and up to four normal deformation sensors (the software calculates automatically the average normal deformation). Loads or deformations for both the shear and normal actuators can be prescribed for automatically performing advanced tests such as the Constant or Calculated Normal Stiffness Direct Shear Test.


Specimens are cured within removable specimen rings and then dropped inside the shear box allowing the preparation of multiple specimens using additional rings increasing test production.


Also available, as an alternative, is an economical Digital Direct Shear system driven with manual pumps.



  • 100 kN shear load capacity
  • 50 kN axial load capacity
  • 150 mm maximum specimen diameter
  • 150 mm maximum specimen height
  • Complete servo-control of both actuators


Please contact GCTS for full specifications.