The direct shear test system is designed to determine the shear strength of intact or jointed rock or concrete specimens. Various samples in the form of cylindrical, prismatic, cubical or irregularly shaped segments of different sizes can be tested by this system. The closed loop servo control shear apparatus includes a special frame construction consisting of two stiff frames for vertical force and shear force, combined in a special configuration to avoid friction and torque. The system includes a hydraulic power pack in combination with two separate valve systems, two-separate controllers and two low friction hydraulic cylinders. The complete system is fully automated and controlled by our flexible and programmable GEOsys software. Various sensors, transducers, shear boxes and experiment options are available.