The ShearTrac III large cyclic direct simple shear (LCDSS) system performs consolidation, static, and cyclic direct simple shear phases on large (12 in/ 305 mm) diameter samples under full automatic control. The DSS test generates a fairly homogeneous state of shear stress throughout the specimen, which provides initial stress conditon, stress path, and deformation configuration that models numerous field loading conditions more closely than any other strength tests (such as triaxial). The system consists of a computercontrolled unit that utilizes a micro-stepper motor to apply the vertical load and an advanced servo motor to apply the horizontal cyclic load to the soil specimen.