Triaxial Testing is used to examine the shear strength of different materials, including soil. It works alongside other testing methods such as Shear Testing and Consolidation Testing to ensure the limits of the material are understood and weaknesses are identified, optimising its performance when supporting a structural frame.

What is Triaxial Testing?

The traditional method of Triaxial Testing involved a mechanical Load Frame (perhaps using interchangeable cogs) with a Triaxial Cell containing the sample. Cell and Back Pressure were applied using compressed air and readings taken on pressure gauges, load rings with dial gauges were used for Load measurement, dial gauge transducers were used for measuring Displacement change and Pore Water Pressure was measured using a digital box (or even a mercury column manometer). Triaxial readings were taken on a periodic basis which required the laboratory technician to be on hand with a clipboard and datasheets to record the different Triaxial data when required throughout the Test

What Are The Benefits Of Automated Triaxial Testing?

The development of automated and semi-automated Triaxial Testing has improved the speed of conducting the test. Faster examination of samples means a larger capacity of tests can be executed which leads to us having an understanding of the sample’s components and behavior when it is put under strain and extreme pressure.

Semi-Automation

The advances in computing power meant that software could be developed to control the different stages of the Triaxial test representing a huge step forward. Additionally, new hardware was developed that assisted the laboratory technician in many ways.

The development of Automatic Pressure Controllers (both Hydraulic and Pneumatic) by VJ Tech enabled Cell and Back Pressure to be controlled automatically and readings sent to the computer via an RS232 Interface.

Load Cells replaced Load Rings, LSCT or Potentiometric Transducers replaced Dial Gauges and Pore Water Pressure Transducers replaced the Digital boxes and mercury column manometers.

VJ Tech Electronic Data Loggers enabled Load, Displacement and Pore Water Pressure measurements to be recorded as specified and then sent to the computer.

The renowned Clisp Studio csTriax software module running on the computer is able to;

• Conform to all major international geotechnical standards
• Set up individual tests based on the Client, Job, Borehole and Sample
• Run multi-stage tests handling up to 4 separate stages for a single specimen
• Run up to 4 specimens within a multi-specimen test
• Run any number or combination of multi-stage or multi-specimen tests at any one time
• Set up and Control the different Instruments and Transducers used in Triaxial Testing
• Calibrate the Transducers when required
• Input Specimen details and automatically calculate related Dimension and Moisture details
• Input the Initial Saturation stage conditions (either Step or Ramp control) for the required number of B-Check schedules, the data logging details and the Stopping conditions for each schedule
• Set the Consolidation stage starting conditions, drainage corrections, data logging parameters and the stopping conditions
• Set up the Shear stage starting conditions, data logging details and stopping criteria
• Display live views of sensor readings and status
• Display live data views, graphs and tables as the test progresses
• Provide complete results data which can be exported to external data processing packages for further manipulation if required
• Produce a number of predefined presentation reports summarising all salient geotechnical results

Although a large part of the Triaxial test was automated, the laboratory technician is still required to intervene during the Saturation stage to open and close the Back Pressure valve as necessary.

Full Automation

When VJ Tech introduced the Automatic Solenoid Valve to the market, full automation was achievable because the Back Pressure valve could now be opened and closed automatically by the software when needed. Once the laboratory technician was happy with the Test setup, options within Clisp Studio allowed one entire test to run to completion, whilst up to 3 other samples could be Saturated and Consolidated automatically, leaving the technician free to perform other duties.

Recent Developments

The new Dual Automatic Pressure Controller (DAPC) was specifically designed by VJ Tech to simplify and modernise the way Triaxial Testing is carried out in soil testing laboratories. Instead of controlling Back and Cell Pressure using two APCs, these two functions can now be performed by a single instrument with two independent pressure cylinders and the added advantage of a significantly smaller footprint.

Another asset of the DAPC is that it is Wi-Fi enabled, thus permitting remote control from a PC or laptop running Clisp Studio software - without lengthy and potentially hazardous cables. The optional 7" touchscreen colour display comes pre-loaded with an Application to remotely control the DAPC (via Wi-Fi) and can be attached magnetically to the instrument for control and status readout.

Purposes built stands are also available for a mobile Compact Triaxial system that can be moved around the laboratory if required.

Speak To VJ Tech For More Information

We are the experts in finding the solution to all your testing requirements. We supply Triaxial Testing equipment that caters to your requirements without compromising on performance. We have been providing our clients with high quality test instruments for over 20 years. Our expertise and experience in the civil engineering industry is second to none and we offer guidance and tailor made solutions to your specific requirements.

Speak to a member of the team today:

Call: +44 (0) 118 945 3737+44 (0) 118 945 3737

Email: service@vjtech.co.uk