If you’re an engineer needing to test material for liquefaction potential, we can help!
After many years of looking into Load Controlled Cyclic Triaxial Strength Testing, we finally made the decision to purchase our own Cyclic (Dynamic) Triaxial Testing equipment in order to provide invaluable data for our clients.
Cyclic Triaxial Testing is performed on soils to evaluate their strength, as well as deformation, under cyclic loading conditions such as earthquakes, wind, waves, passing trains, and more.
Our new Cyclic Triaxial equipment is based in our Auckland laboratory, and is capable of testing a wide range of soils, particularly those that cannot be appropriately assessed using the conventional simplified CPT and SPT based methods, including pumice sands, pleistocene aged soil and silty soil.
The cyclic strength is affected by many factors, including sample density, grain structure, and stress history. However, the most important factor to consider is sample handling and preparation.
The testing is very technical and complex, therefore the samples are extremely delicate to handle. They are frozen on site and then transported in this frozen state to minimise any disturbance, as well as to preserve the intact structure and density.
With Cyclic Triaxial Testing having much stricter requirements on sample quality, the samples are very sensitive in the preparation stage. Through our many test runs, it has been shown that different methods of preparation can result in significantly different strength results.
As well as performing the usual Cyclic Triaxial test, we also carry out Bender Element tests to determine the shear wave velocity in soil specimens. During this test, a shear wave is generated at one end of the specimen, transmitted through the sample, and then received at the opposite boundary. The shear wave travel distance is identified, the travel time is measured, and the shear wave velocity can then be calculated accordingly.
Our specialist laboratory team have completed many system trials to ensure the data we’re getting is reliable. This included testing on known materials such as Toyoura sand and then comparing the results with published research.
Since then, we have carried out tests on multiple projects, including the measurement of small strain shear modulus, with Bender Element testing.
We are extremely proud to be the first commercial laboratory in New Zealand to offer this specialised Cyclic Triaxial Testing and provide our clients with more accurate, representative results.