Cyclic Direct Simple Shear (Cyclic DSS) Test System

ShearTrac II

The ShearTrac II cyclic direct simple shear (CDSS) system performs the consolidation and cyclic shear phases of a test under fully automatic control. Typical applications include earthquake engineering, liquefaction analysis, or offshore studies. 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 other strength tests (such as triaxial). The system utilizes a micro-stepper motor to apply the vertical load and an advanced zero-backlash servo actuation system to apply shear force and displacement to the soil specimen.

Applicable Test Standards

• ASTM D2166, D2435, D3080, D4186, D4546, D6528, D8296
• AASHTO T 208, T 216, T 236
• B 1377-5, 1377-7
• ISO/TS 17892-5, 17892-10
• AS 1289.6.6.1, 1289.6.2.2

Features

• Fully automated via computer or standalone capability for control and data collection
• Micro-stepper & servo electronic motor systems offers high speed and precise loading
• Zero backlash servo actuation system
• More accurate, reliable, and easier to maintain than units requiring hydraulics or air pressure
• Passive or active height control
• Highly rigid frame and an innovative mechanical locking system for reliable passive volume control
• Conduct static or cyclic tests in drained (constant load) and undrained (constant volume) condition
• Consolidate with or without initial shear stress
• Stress or strain controlled sinusoidal and irregular user-defined waveforms
• Apply irregular stress ratio and strain time history (e.g. earthquake motion)
• Post cyclic drained/undrained shearing
• Software configurable excitation voltage for sensors
• Remote network access for real-time monitoring and control
• Software generates full report of the test or raw data (.CSV export)
• System flexibility to optionally perform Direct/Residual Shear, 1-D Incremental Consolidation, Constant Rate-of-Strain (CRS) Consolidation, and Unconfined Compression testing

Specifications

• Horizontal loading capacity: 4.5 kN (1000 lbf) standard
• Vertical loading capacity: 11 kN (2500 lbf) standard
• Horizontal displacement: cyclic peak to peak strain of up to 10%; monotonic strain of up to 25%
• Vertical displacement: 50 mm (2.0 in)
• Cyclic rate: Up to 5 Hz; Typical test range 0.033 to 2 Hz
• Dimensions: 660 x 406 x 813 mm (26 x 16 x 32 in)
• Weight: 63 kg (140 lbs)
• Test accessories, including Teflon® coated shear rings, available diameters: 50 mm (2.0 in), 63.5 mm (2.5 in), or 100 mm (4.0 in)