Soil and Asphalt Direct Shear Testing System
SDS-150 Direct Shear Testing System for Soils and Asphalts

The GCTS SDS-150 Direct Shear Testing System is excellent for measuring the shear strength properties of soil and asphalts. With its advanced design, testing is extremely precise while being very easy-to-use for the greatest testing experience.


  • Closed-loop servo control of double acting shear load actuator
  • Shear load capacity of 50 kN (5 ton) with 100 mm stroke
  • Normal load capacity of 50 kN (5 ton) with 50 mm stroke
  • Normal load reaction support mounted on sliding bearings to minimize horizontal friction
  • Cubical specimen of up to 150 mm (6 in.) sides
  • Software for automatic performance of direct shear tests with constant normal stress or constant normal stiffness
  • Real-time graphical display of the test progress

The GCTS Direct Shear Testing Systems feature electro-hydraulic closed-loop digital servo control of the shear and normal loads to automatically perform conventional direct shear tests as well as more advanced tests. These systems can be easily programmed to perform tests where the normal load is a function of a prescribed stiffness to simulate actual compressibility of a ground shear plane.


The top shear box can be horizontally translated and the bottom shear box is mounted on pre-loaded sliding bearings to minimize horizontal friction. Set screws with nylon tips are used to adjust the shear gap and the top shear box is suspended on springs that balance its own weight. This allows for different shear gap settings and the more precise measurement and control of the normal stress.


Included with these systems are loading plates with a square grid of retractable pins that help to grab different types of samples, such as soils, asphalt and other materials. Also included is a water reservoir to submerge specimens during testing.


The SDS systems are especially well-suited to test coarse granular materials and simulate interface materials because of their high load capacity, ability to accommodate large specimens, and elimination of vibrations that can disturb or compact granular specimens.


  • 50 kN axial load capacity
  • 50 kN shear load capacity
  • 150 mm x 150 mm x 75 mm maximum size specimens


Please contact GCTS for full specifications.