Window and Windowless Sampling

Window and windowless sampling are methods of soil extraction that retain the various horizons of the soil, so that they may be analysed, measured and profiled. To achieve this steel tubes (typically 1 metre in length) are pounded into the ground using one of two tools.

The first and most common tool for the job is the Archway Lightweight Dart Rig. This versatile rig uses a 63.5kg weight to hammer plastic lined windowless tubes into the ground to collect samples. The tracked rig allows us to complete windowless samples to a typical depth in the order 5.00-6.00m below ground level, navigating uneven terrain to achieve this. Another benefit of the dart rig is that not only can it extract the sampling tubes, but it can also perform other functions such as dynamic probe testing, borehole installation, standard and cone penetration tests.

The second method of window sampling is to use a handheld device. For this we use a JCB hydraulic breaker attached to window sampling tubes which are driven into the sub-surface, and subsequently extracted using hydraulic jacks. This method is typically used in areas of limited access and in cases of investigation to shallow soils.

Extracted samples will show an intact picture through the soil. From this, we’re able to measure and log the various strata present in the location. It is also possible to use samples acquired for further testing, as outlined on our lab testing page.

The differences between Window and windowless sampling are minimal. As the name suggests, a window sample tube has a slot cut out the length of the tube, acting as a window for quick and easy observations. It also has the added benefit of being lighter than its counterpart which is ideal when wielding handheld devices. The windowless sample tube doesn’t have this window. Instead, the sample is retained in the plastic sleeve that lines the sampling tube. Because there is no slot cut out of the windowless sample tubes, they are much better suited to withstanding the rigours that come with being pounded by a 63kg hammer.

Besides the advantages already outlined above, window and windowless sampling also have the benefit of being very cost efficient, especially when combined with other testing and drilling.

If you have the need for some window or windowless sampling, please contact one of our engineers for a competitive quote. To find out more about our other geotechnical services, click here