【国外标准】 Standard Practice for Sampling Soils and Contaminated Media with Hand-Operated Bucket Augers

5.1 Bucket augers (Fig. 1) are relatively inexpensive, readily available, available in different types depending on the media to be sampled, and most can be easily operated by one person. They collect a reasonably cylindrical but disturbed sample of surface or subsurface soil or waste. They are generally not suited for sampling gravelly or coarser soil and are unsuitable for sampling rock. There are other designs of hand augers, such as the Edelman auger, used to retrieve difficult materials such as waste, sands, peat, and mud.FIG. 1 Bucket Auger5.2 Bucket augers are commonly used equipment because they are inexpensive to operate, especially compared to powered equipment (that is, direct push and drill rigs). When evaluated against screw augers (Guide D4700), bucket augers generally collect larger samples with less chance of mixing with soil from shallow depths because the sample is retained within the auger bucket. Bucket augers are commonly used to depths of 3 m but have been used to much greater depths depending upon the soil or waste characteristics. In general, bucket augers can maintain open holes in unsaturated soils and saturated clay soils below the water table. Saturated sands will cave below the water table and perched zones and cohesionless dry sands may also cave. The sampling depth is limited by the force required to rotate the auger and the depth at which the bore hole collapses (unless bore casings or liners are used).5.3 Bucket augers may not be suitable for the collection of samples for determination of volatile organic compounds (VOCs) because the sample is disturbed and exposed to atmosphere during the collection process, which may lead to losses resulting in a chemically unrepresentative sample.5.4 If VOC analysis is required, the bucket auger is used to reach the desired sample depth, a planer auger can be used to clean the base of the hole, and a hammered drive tube sampler (Fig. 2) can be used at the bottom of the hole. Drive tube samplers can be sealed and capped. Consult Guide D4547 on practices for immediate subsampling of soil cores for VOCs. Drive tubes that are not full and contain disturbed material and are exposed to air may not provide accurate VOC data. For the best results, the core sample can be extruded from the tube and immediately subsampled.FIG. 2 Soil Core Sampler System1.1 This practice describes the procedures and equipment used to collect surface and subsurface soil and contaminated media samples for chemical analysis using a hand-operated bucket auger (sometimes referred to as a barrel auger). Several types of bucket augers exist and are designed for sampling various types of soil. All bucket augers collect disturbed samples. Bucket augers can also be used to auger to the desired sampling depth and then, using a core-type sampler, collect a relatively undisturbed sample suitable for chemical analysis.1.2 This practice does not cover the use of large 300 mm or greater diameter bucket augers mechanically operated by large drill rigs or similar equipment, such as those described in Practice D1452/D1452M, paragraph 5.2.4. Practice D1452/D1452M on auger borings refers to this hand auger included in Practice D6907 as a barrel auger.1.3 Refer to Guides D4700 and D6232 for information on other hand samplers. The bucket auger is often used for shallow surface soil sampling, but there are many other types of handheld augers, flight, screw, rotary powered, and agricultural push tube samplers. Practice D1452/D1452M addresses larger powered solid stem flight auger systems.1.4 This standard does not address soil samples obtained with mechanical drilling, direct push, and sonic machines (refer to Guides D6286/D6286M and D6169/D6169M) or for collecting cores from submerged sediments (Guide D4823).1.5 This practice does not address sampling objectives (see Practice D5792), general sample planning (see Guide D4687), and sampling design (for example, where to collect samples and what depth to sample (see Guide D6044)). Sampling for volatile organic compounds (see Guide D4547), equipment cleaning and decontamination (see Practice D5088), sample handling after collection such as compositing and subsampling (see Guide D6051), and sample preservation (Guide D4220/D4220M) are used in this standard.1.6 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.1.7 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. 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.1.8 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.9 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.