Cyclic simple shear


The ShearTrac II-DSS system is a universal shear system capable of performing the consoli-dation, static and cyclic direct simple shear phases under full automatic control. This sys-tem is of the type developed at NGI in the mid 1960's. The DSS test generates a fairly homogeneous state of shear stress throughout the specimen, which provides initial stress condition, 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 computer-controlled unit that utilizes micro-stepper motors to apply the vertical and horizontal loads to the soil specimen.

The system is capable of running a consolidation phase for up to 32 increments automatically. Stress controlled cyclic can be applied up to a frequency of 1 Hz that can be followed by simple shearing at a specified rate of deformation or force. The constant volume condition is maintained through a closed loop computer control with the vertical displacement sensor as the feed back. The system is capable of display-ing the current status of a test and graphically portraying the progress of the test in real time. The system includes the capability for the operator to alter the test process and conditions at any stage of the test.

The system comes complete with hardware and software for recording all test input data and settings of ed test parameters, performing standard engineering calculations on the data, and producing graphically plotted and printed output. 


Choose load capacity to fit user needs up to 5kN (1,000 lbs.)

Total automation, control, data collection and re-porting of test results

Prepare tables and plots of report quality within minutes of completing a test

Geo-NET compatibility lets unit be accessed and controlled over a computer network

Generate columns of data for easy reduction using your own spreadsheet software

Accurate displacement rate control from 0.00003 to15 mm per minute (0.000001 to 0.6 in. per minute)

Select number of data points logged per cycle form 10 to 500 readings per second

Manual control capability through front keypad and LCD menus

Versatile system 


ASTM D 6528 Consolidated Undrained Direct Sim-ple Shear Testing of Cohesive Soils

ASTM D2435/T216 One-Dimensional Consolida-tion Properties of Soils 



CAPACITYUp to 4.4 kN (1,000 lbs.)
VERTICAL FORCEStepper motor with built-in controls for vertical load and displacement
HORIZONTAL FORCEStepper motor with built-in controls for horizontal load and displacement
SPEED RANGE0.00003 to 15 mm per min. (0.000001 to 0.6 in per minute)
HORIZONTAL TRAVEL±12.5 mm (±0.50 in.) resolved to 0.0013 mm (0.00005 inches)
VERTICAL TRAVEL25.45 mm (1.00 in.) resolved to 0.0013 mm (0.00005 inches)
POWERSingle Phase 208 VAC/6oHz (US) / 220 VAC/50HZ (international)
DIMENSIONS228 mm x 560 mm x 762 mm (9 in. x 22   in. x 30 in.)
WEIGHT63 kg (140 lbs.)
DIAMETER2.5 in. (63.5 mm) up to 4.0 in.(101.5 mm)
ACCESSORIESGeo-NET-PC Network/Communication card to link ShearTrac II-DSS to PC. Teflon-coated stacked rings, and stainless steel trimming ring
SOFTWARE MODULECyclic DSS Software package to automatically run and edit cyclic and static direct simple shear test
OPTIONSDirect/Residual Shear, Incremental Consolidation, and CRC options available upon request

For viewing forms of the report and the interface of the operating program click the mouse on a corresponding miniature.