Civil and Building Engineering.

The ASTM has published a detailed standard (1587) for thin-walled tube sampling of soils. The specified dimensions of sampling tubes are shown in Figure 4.4.

Two mounting holes are required for 2- to 3.5-in. samplers and four mounting holes for larger sizes. Hardened screws are required for the mounting.

Dimensions for tubes of three diameters are given in Table 4.1, but tubes of intermediate or larger sizes are acceptable. The lengths shown are for illustration; the proper length is to be determined by field conditions.
The preparation of the tip of the sampler is specified, and the clearance of 1 percent is designed to minimize disturbance due to resistance to penetration of the sample. The interior of the sampling tube must be clean, and a coating is sometimes recommended. Procedures for the transportation of thin-walled tubes are specified in ASTM D 4220, Standard Practice for Preserving and Transporting Soil Samples.
Special tools have been developed to eliminate disturbance partially due to the interior resistance of the sampling tool. At the Swedish Geotechnical Institute, a sample more than 2 m long was laid out for examination. The sample had been taken by the Swedish Foil Sampler, which consisted of a short, thin-walled section followed by a thick-walled section in which was embedded a series of rolls of foil. As the sample was pushed into full penetration, the rolls of foil were simultaneously pulled back to eliminate completely resistance due to sample penetration. The description of a similar device is presented in ASTM D 3550, Standard Practice for Ring-Lined Barrel Sampling of Soils. A sketch of the sampling tool is shown in Figure 4.5. The ASTM Book of Standards presents 13 standards, in addition to D1587, related to surface and subsurface characterization of soil and rock. A list of the relevant ASTM standards is presented in Appendix 4.1.