High-Capacity Direct Shear Apparatus

The High-Capacity Direct Shear Machine has been specifically designed for testing large, 12" (305mm) square soil sample sizes of soil and soil/geosynthetics. Samples are mounted in a two-piece shear ring assembly, horizontally divided in half. The bottom half is held securely in place while a vertical confining force is applied. Horizontal force is then directed against the upper half of the ring to shear the specimen.

Sample loads are obtained by the use of four pneumatic pistons. This concept increases the accuracy and sensitivity of light load settings. Two, small-diameter rolling diaphragm pistons are capable of applying light loads to 1,000 lbs (454kg) and the two, larger pistons apply loads up to 10,000 lbs (45kN) or 20,000 lbs (90kN) depending on the model.
In stand-alone mode, these direct shear machines provide a 7" (178mm) touch-screen controller, giving you finger-tip control of your testing processes, as well as providing real-time, visual views of your data in both tabular and graphic formats.

These new waterproof, touch screens provide colorful, at-a-glance monitoring of testing functions without the use of a computer. Operators can see all the data in several formats at the machine while the test is running. Data can then be viewed simultaneously or downloaded later to a computer in the lab, in the next room or at a different location, while also providing report generation capabilities from within Humboldt's NEXT software or our enhanced HM-5700SW Direct Shear software module.
When operated from a networked computer the NEXT software provides robust machine and test control, and report generation. It also allows the ability to control and monitor multiple machines from a single computer. Applying the vertical load is accomplished by setting the precision regulator to the required pressure per the calibration chart. Load settings are verified on a pressure readout that reads to two decimal places and is accurate to 0.25%. The horizontal shear rate is set using the digital thumb wheel on the control panel. Limit switches are used to set the home position of the shear rings and to limit the travel to 4" (300mm).
Consolidation and shear displacement are measured by linear displacement transducers and displayed on the digital readout. Shear load is measured from a load cell attached to the water chamber. The included software imports data onto spreadsheets such as Excel® for analysis and reporting. Displayed values on the readout can be viewed at anytime.
Loading and unloading the specimen and shear ring assembly to and from the water chamber is simplified using the Compaction Table. Pulling the loaded shear rings onto the convenient table rollers allows the entire assembly to slide easily into and out of the chamber. Sample compaction, geotextile placement, and specimen preparation can be performed on the table, before placing the assembly directly into the water chamber with little effort.
The direct shear is designed for harsh lab environments. All steel parts are powder coated and aluminum parts are hard-coat anodized for corrosion resistance. Casters on the machine and compaction table allow for easy movement in the lab.
These direct shear machines include the compaction table and the top and bottom shear rings. The top ring measures 12" x 12" x 4" (305 x 305 x 102mm), and the bottom ring measures 12" x 16" x 4" (305 x 406 x 102mm). Software and data cable are also included. A 120psi (827kPa) source of clean, dry, compressed air is required for operation.