Direct Shear Machines (Pneumatic)

Gilson Pneumatic Direct Shear Machines are tabletop units manufactured in cooperation with Karol-Warner and provide direct or direct/residual shear values for evaluating the strength and stability of soils.

Soil specimens are carefully trimmed into a Direct Shear Box, which is horizontally divided, allowing independent movement of the upper and lower halves. A vertical confining load is applied to the specimen, and a horizontal shear force is applied to the lower half of the shear box, while the upper half remains stationary. After a direct shear failure has been measured, selected models allow the force direction to be reversed to determine residual shear values.

Pneumatic Direct Shear Machines apply vertical confining pressures to the specimen. Confining loads are applied pneumatically using a small, rolling diaphragm piston for light loads of 4–100lbf (0.018–0.44kN) and a larger diameter piston for loads up to 1,500lbf (6.67kN). This design increases the sensitivity and accuracy of the light load system. Loading is controlled using the precision regulator with an included calibration chart. Load settings are displayed digitally and are accurate to ±0.25%. Both pneumatic direct shear machines are completely self-contained, and the need for loading weights is eliminated.

A stepper motor controls strain rates to ±1% from 0.0001 to 0.3in/min (0.0025 to 7.62mm/ min) and is easily set with digital thumbwheel controls. The total shear capacity is 1,500lbf (6.67kN). The included water chamber with drainage port is constructed of Teflon-coated, anodized aluminum for corrosion resistance.

HM-381 Standard Pneumatic Direct Shear Machine uses an S-Type Load Cell connected to a built-in digital display to measure and display load values. Consolidation and direct shear displacement are measured using analog dial indicators.

HM-382 Digital Pneumatic Direct Shear Machine also includes an S-Type Load Cell to measure shear load but adds Linear Variable Displacement Transducers (LVDTs) to measure horizontal and vertical displacement and functionality to perform residual shear testing. A Four-Channel Data Readout with mini USB data output processes and displays measured values. GetData 5 software is included to transfer data in ASCII format to common spreadsheet applications in the user’s computer using Windows XP or a newer operating system.

Features:

• The pneumatic system applies vertical confining pressures – no weights are required
• Load cell with data readout displays shear load values
• Total shear capacity of 1,500lbf (6.67kN)
• Stepper motor controls strain rates to ±1% from 0.0001 to 0.3in/min (0.0025 to 7.62mm/ min)
• HM-382 performs both direct and residual shear tests

Included Items:

• Standard Pneumatic Shear Machine (120V, 50/60Hz or 230V, 50/60Hz)
  
  • Analog dial indicators
  • S-Type load cell
  • Water chamber with drainage port
  • 15ft Air supply tubing
• Digital Pneumatic Shear Machine (120V, 50/60Hz or 230V, 50/60Hz)
  
  • Linear variable displacement transducers
  • S-Type load cell
  • Four-Channel data readout
  • GetData 5 software
  • Water chamber with drainage port
  • 15ft Air supply tubing

Accessories:

• Shear Boxes are available in popular sizes for round or square specimens
• Direct Shear Accessories include Cutters (sample rings) with built-in cutting edges, Extruders for removal of specimens from sample rings, and Porous Stones, all available in popular round or square specimen sizes.
• Data Readouts with two or four channels, display readings from load cells and transducers
• HM-739 1in Linear Variable Displacement Transducer for the electronic measurement of displacement
• HMA-95 Pneumatic Shear Machine Rolling Cart offers mobility and positions load frames at the proper working height
• HMA-610 Direct/Residual Shear Data Acquisition Software records specimen and real-time test data to calculate results and prepare reports following ASTM and AASHTO requirements.
• HMA-739 Shear Box Counterbalance offsets the weight of the top half of the Shear Box. Inquire for Counterbalances for larger sizes.
• MA-363 Digital Dial Indicator 0.6x0.0001in (Range & Resolution) for digital display of displacement measurements
• MA-366 Digital Dial Indicator 1x0.0001in (Range & Resolution) analog measurement of displacement and movement

Related blogs:

• Soil Direct Shear Test: Understanding the Process