The GCTS Direct Shear Systems for Rocks are simple and inexpensive devices capable of performing direct shear tests on a wide variety of rock specimens. These systems are ideal for performing direct shear tests, as all testing procedures can be automated through the use of our advanced software and all test data is automatically analyzed at the end of the test. 

The GCTS Direct Shear Systems for Rocks feature:

• Closed-loop servo control of a double acting (push and pull), 100 kN (10 ton) shear load actuator with a 25 mm stroke and a 50 kN (5 ton) normal load actuator with a 25 mm stroke
• Stiff normal load reaction frame mounted on sliding bearings, which minimize horizontal friction while keeping the normal load vertical throughout the shear displacement
• 150 mm (6 inch) diameter sample rings for specimen below 150 mm in height
• Advanced software for automatic performance of direct shear tests with either a constant normal stress or a constant normal stiffness
• Real-time graphical display of test progress
• Other systems available upon request with different load capabilities (up to 1,000 kN), different specimen dimensions (up to 300 mm), and hydraulic control of the shear load actuator
• Direct Shear Systems are also available for Soils and Asphalts

Relevant Standards

ASTM D4554 Standard Test Method for In Situ Determination of Direct Shear Strength of Rock Discontinuities

ASTM D5607 Standard Test Method for Performing Laboratory Direct Shear Strength Tests of Rock Specimens Under Constant Normal Force

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 Direct Shear System for Rocks is an inexpensive apparatus used to test many configurations of rock specimens. Prisms, cubes, fragments, and cylindrical specimens can all be used in the test to determine the shear strength of the rock.

This system contains closed-loop, servo-controlled, electro-hydraulic shear and normal load actuators which, in conjunction with the advanced GCTS software, allow for automatic performance of a Direct Shear Test. The software uses inputs from up to four normal deformation sensors and the normal load sensor to automatically calculate the average normal deformation of the specimen. This allows for the system to automatically perform either a constant normal stress or a constant normal stiffness test. 

Specimen are created inside removable specimen rings and placed inside the shear box, which allows multiple specimens to be prepared simultaneously, increasing laboratory productivity. 

Systems are available for larger load capacities and larger diameter specimens. A more economical, manual pump system is also available as an alternative.

Please contact GCTS for full specifications.