Considering the limitations of dynamic probing, Substruck recommends that at least one sample should be taken on each site. BS 5930:2015 identifies dynamic sampling as a popular method for shallow sampling due to the recovery of a reasonably complete soil profile, a general absence of spoil, the relatively small size and light weight of the equipment, which makes for easier access on restricted sites, smaller transport requirements and lower costs.
The requirements for soil sampling, according to IS EN 1997-1 and IS EN 1997-2, are specified in EN ISO 22475-1 Geotechnical investigation and testing – Sampling methods and groundwater measurements – Part 1: Technical Principles of Execution. Substruck uses dynamic windowless sampling. As outlined in the Code of practice for site investigations, this system is best suited to dry cohesive soils where samples of quality class 3 or 4 are obtainable. In ideal conditions, it is possible to take a sequence of samples down to a maximum depth of about 8 m. In cohesionless soils, samples of quality class 5 are produced. Windowless sampling tubes do not have slots, with a plastic liner being inserted into the steel tube. The soil recovered can be retained as a sample in the plastic liner or as disturbed samples taken from it. Sample catchers can be included between the cutting shoe and sample liner to retain soil.