4.1 The thick-wall ring lined drive sampler has been used for over 50 years in the arid southwest regions of the U.S. where unsaturated soils are too difficult to sample using the thin-walled tube (Practice D1587). Variations of the sampler include names such as “Dames and Moore, California, Modified California barrels” with outside barrel diameters ranging from 2.5 to 3.5 in. [60-90 mm].4 In addition to the blow count, these drive samplers have the added benefit of having a ring lined specimens that can be evaluated in the laboratory. Versions of the original Dames and Moore type sampler shown in Fig. 1 are still used, but many now use the Diamond Drill Core Manufacturers Association (DCDMA)5 specification split barrel drive samplers Fig. 2. The ring lined samplers normally have provisions for a 6-in. [150 mm] waste barrel with or without rings in the top section of the barrel. Drilling in the unsaturated soils is performed almost exclusively with hollow-stem augers (Practice D6151) because it is a dry drilling method. The test can be performed in fluid rotary or other drill holes but use of fluid rotary methods are not recommended in unsaturated soils as the drill fluid may alter the sample properties. Most operators use a 140 lb [75 kg] hammer mass but other hammer masses may be used.

1.1 This practice covers procedure for thick wall, split barrel drive sampling of soil to obtain representative samples of soil for classification and laboratory testing. The sampler is considered to be a thick wall sampler with sharpened cutting shoe and ball check vent. The middle barrel section is split barrel design containing ring liners. The sampler is often driven, but can also be pushed in softer deposits. Penetration resistance data may be recorded. This standard uses procedures similar to Test Method D1586 on Penetration Resistance and Split Barrel Sampling of Soils. However, in this practice, differing hammer weights, drop heights, and different size samplers are used, so the data must not be reported as conforming to Test Method D1586 and cannot be used to determine Normalized penetration resistance data for sands in accordance with Practice D6066.

1.2 This practice involves use of rotary drilling equipment (Guide D5783, Practice D6151). Other drilling and sampling procedures (Guide D6286, Guide D6169) are available and may be more appropriate. Considerations for hand driving or shallow sampling without boreholes are not addressed. Subsurface explorations should be recorded in accordance with Guide D5434. Soil samples should be classified in accordance with Practice D2488.

1.3 The soil samples from this test will have some degree of disturbance because the sampler is a driven thick walled sample tube. Table 2 of Guide D6169 on Soil and Rock Sampling provides guidance for selection of soil samplers for samples that may require intact samples defined by Terminology D653 for laboratory testing. The degree of disturbance must be evaluated by the user (engineer) to determine the suitability of the sample for use in laboratory tests. If samples are not suitable for laboratory testing, other soil samplers should be used (see 4.4.1).

1.4 The values stated in either inch-pound units or SI units [presented in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard

1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026, unless superseded by this standard.

1.6 This practice offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgement. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.

1.6.1 This practice does not purport to comprehensively address all of the methods and the issues associated with soil sampling. Users should seek qualified professionals for the decisions as to the proper equipment and methods that would be most successful for their site exploration. Other methods may be available for monitoring soil sampling and qualified professionals should have flexibility to exercise judgement as to possible alternatives not covered in this practice.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices. The user must comply with prevalent regulatory codes, such as OSHA (Occupational Health and Safety Administration) guidelines while using this practice. For good safety practice, consult applicable OSHA regulations and other safety guides on drilling.2

1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.