Tech Review: Dual Tube Continuous Soil Sampling Systems DT325-DT45

In Australia, Geoprobe's Dual-Tube 3.25 in. (DT325) soil sampling system has been the gold standard for environmental site investigations since the early 2000s. By enabling rapid collection of continuous, representative samples, the DT325 system has contributed to improve the vertical and horizontal delineation of subsurface contaminants in hundreds of sites across the country. Furthermore, the DT325 is one of the most cost-effective methods for stratigraphic characterisation and collection of samples for particle-size analysis and other identification tests, which makes it also interesting to hydrogeologists and geotechnical engineers.

In addition, Legion Drilling also owns Dual Tube 4.5" (DT45) systems, whose wider diameter enable various types of installations installations and testing to be performed. This includes installation of pre-packed wells and completion of geotechnical testing methods.

The DT325 and DT45 systems utilise a cutting shoe, sheath, sample retainer and more importantly dual rods, ensuring the bore is fully cased during sampling. This prevents cross-contamination and protects against bore collapse, delivering high-quality results in diverse formations. The outer rods can also be employed to do installations (e.g., pre-packed wells) while minimising the production of drilling-derived waste. DT325 and DT45 have a small environmental footprint, avoiding the production of drill cuttings and aligning with the growing demand for sustainable practices in environmental and geotechnical site investigations.

Check out Legion's website for further details on DT325, DT45 and other soil sampling technologies.