1、Designation: D 4700 91 (Reapproved 2006)Standard Guide forSoil Sampling from the Vadose Zone1This standard is issued under the fixed designation D 4700; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers procedures that may be used forobtaining soil samples from the vadose zone (unsaturatedzone). Samples can be collecte
3、d for a variety of reasonsincluding the following:1.1.1 Stratigraphic description,1.1.2 Hydraulic conductivity testing,1.1.3 Moisture content measurement,1.1.4 Moisture release curve construction,1.1.5 Geotechnical testing,1.1.6 Soil gas analyses,1.1.7 Microorganism extraction, or1.1.8 Pore liquid a
4、nd soils chemical analyses.1.2 This guide focuses on methods that provide soil samplesfor chemical analyses of the soil or contained liquids orcontaminants. However, comments on how methods may bemodified for other objectives are included.1.3 This guide does not describe sampling methods forlithifie
5、d deposits and rocks (for example, sandstone, shale, tuff,granite).1.4 In general, it is prudent to perform all field work with atleast two people present. This increases safety and facilitatesefficient data collection.1.5 The values stated in inch-pound units are to be regardedas standard. The valu
6、es given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to esta
7、blish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.7 This guide offers an organized collection of informationor a series of options and does not recommend a specificcourse of action. This document cannot replace education orexperi
8、ence and should be used in conjunction with professionaljudgment. Not all aspects of this guide may be applicable in allcircumstances. This ASTM standard is not intended to repre-sent or replace the standard of care by which the adequacy ofa given professional service must be judged, nor should this
9、document be applied without consideration of a projects manyunique aspects. The word “Standard” in the title of thisdocument means only that the document has been approvedthrough the ASTM consensus process.2. Referenced Documents2.1 ASTM Standards:2D 653 Terminology Relating to Soil, Rock, and Conta
10、inedFluidsD 1452 Practice for Soil Investigation and Sampling byAuger BoringsD 1586 Test Method for Penetration Test and Split-BarrelSampling of SoilsD 1587 Practice for Thin-Walled Tube Sampling of Soilsfor Geotechnical PurposesD 2488 Practice for Description and Identification of Soils(Visual-Manu
11、al Procedure)D 3550 Practice for Thick Wall, Ring-Lined, Split Barrel,Drive Sampling of SoilsD 4220 Practices for Preserving and Transporting SoilSamples3. Terminology3.1 Definitions:3.1.1 Except where noted, all terms and symbols in thisguide are in accordance with the following publications. Inord
12、er of consideration they are:3.1.1.1 Terminology D 653.3.1.1.2 Compilation of ASTM Standard Terminology,3and3.1.1.3 Websters New Collegiate Dictionary.43.1.2 For definitions and classifications of soil related termsused, refer to Practice D 2488 and Terminology D 653. Addi-tional terms that require
13、clarification are defined in 3.2.1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.21 on Ground Water andVadose Zone Investigations.Current edition approved July 1, 2006. Published August 2006. Originallyapproved in 1991.
14、Last previous edition approved in 1998 as D 4700 91 (1998)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.
15、3Compilation of ASTM Standard Terminology, Sixth edition, ASTM Interna-tional, 100 Barr Harbor Drive, West Conshohocken, PA, 1986.4Websters New Collegiate Dictionary, Fifth edition, 1977.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United State
16、s.3.2 Definitions of Terms Specific to This Standard:3.2.1 cascading waterperched ground water that enters awell casing via cracks or uncovered perforations, trickling, orpouring down the inside of the casing.3.2.2 sludgea water charged sedimentary deposit.3.2.2.1 DiscussionThe water-formed sediment
17、ary depositmay include all suspended solids carried by the water and traceelements that were in solution in the water. Sludge usually doesnot cohere sufficiently to retain its physical shape whenmechanical means are used to remove it from the surface onwhich it deposits, but it may be baked in place
18、 and be adherent.4. Summary of Guide4.1 Sampling vadose zone soil involves inserting into theground a device that retains and recovers a sample. Devicesand systems for vadose zone sampling are divided into twogeneral groups, namely the following: samplers used in con-junction with hand operated devi
19、ces; and samplers used inconjunction with multipurpose or auger drill rigs. This guidediscusses these groups and their associated practices.4.2 The discussion of each device is organized into threesections, describing the device, describing sampling methods,and limitations and advantages of its use.
20、4.3 This guide identifies and describes a number of sam-pling methods and samplers. It is advisable to consult availablesite-specific geological and hydrological data to assist indetermining the sampling method and sampler best suited for aspecific project. It is also advisable to contact a local fi
21、rmproviding the services required as not all sampling and drillingmethods described in this guide are available nationwide.5. Significance and Use5.1 Chemical analyses of liquids, solids, and gases from thevadose zone can provide information on the presence, possiblesource, migration route, and phys
22、ical-chemical behavior ofcontaminants. Remedial or mitigating measures can be formu-lated based on this information. This guide describes devicesand procedures that can be used to obtain vadose zone soilsamples.5.2 Soil sampling is useful for the reasons presented inSection 1. However, it should be
23、recognized that the generalmethod is destructive, and that resampling at an exact locationis not possible. Therefore, if a long term monitoring program isbeing designed, other methods for obtaining samples should beconsidered.6. Criteria for Selecting Soil Samplers6.1 Important criteria to consider
24、when selecting devices forvadose zone soil sampling include the following:6.1.1 Type of sample: An encased core sample, an uncasedcore sample, a depth-specific representative sample, or asample according to requirements of the analyses,6.1.2 Sample size requirements,6.1.3 Suitability for sampling va
25、rious soil types,6.1.4 Maximum sampling depth,6.1.5 Suitability for sampling soils under various moistureconditions,6.1.6 Ability to minimize cross contamination,6.1.7 Accessibility to the sampling site, and6.1.8 Personnel requirements.6.2 The sampling devices described in this guide have beenevalua
26、ted for these criteria. The results are summarized in Fig.1.7. Sampling with Hand Operated Devices7.1 These devices, that have mostly been developed foragricultural purposes, include:7.1.1 Screw-type augers,7.1.2 Barrel augers,7.1.3 Tube-type samplers,7.1.4 Hand held power augers, and7.1.5 Trench sa
27、mpling with shovels in conjunction withmachine excavations.7.2 The advantages of using hand operated devices overdrill rigs are the ease of equipment transport to locations withpoor vehicle access, and the lower costs of setup and decon-tamination. However, a major disadvantage is that thesedevices
28、are limited to shallower depths than drill rigs.7.3 Screw-Type Augers:7.3.1 DescriptionThe screw or ship auger is essentially asmall diameter (for example, 1.5 in. (3.81 cm) wood augerfrom which the cutting side flanges and tip have been removed(1)5(see Fig. 2(a). According to the Soil Survey Staff
29、(1), thespiral part of the auger should be about 7 in. (18 cm) long, withthe distances between flights about the same as the diameter(for example, 1.5 in.) of the auger. This facilitates measuringthe depth of penetration of the tool. Variations on this designinclude the closed spiral auger and the J
30、amaica open spiralauger (2) (see Fig. 2(b) and (c). The auger is welded onto alength of solid or tubular rod. The upper end of this rod isthreaded, to accept a handle or extension rods. As manyextensions are used as are required to reach the target samplingdepth. The rod and the extensions are marke
31、d in even incre-ments (for example, in 6-in. (15.24-cm) increments) above thebase of the auger to aid in determining drilling depth. Awooden or metal handle fits into a tee-type coupling, screwedinto the uppermost extension rod.5The boldface numbers in parentheses refer to the list of references at
32、the end ofthe text.FIG. 1 Criteria for Selecting Soil Sampling EquipmentD 4700 91 (2006)27.3.2 Sampling MethodFor drilling, the auger is rotatedmanually. The operator may have to apply downward pressureto start and embed the auger; afterwards, the auger screws itselfinto the soil. The auger is advan
33、ced to its full length, and thenpulled up and removed. Soil from the deepest interval pen-etrated by the auger is retained on the auger flights. A samplecan be collected from the flights using a spatula. A foot pumpoperated hydraulic system has been developed to advanceaugers up to 4.5 in. (11.43 cm
34、) in diameter. This largerdiameter allows insertion of other sampling devices into thedrill hole, once the auger is removed, if desired (3).67.3.3 CommentsSamples obtained with screw-type sam-plers are disturbed and are not truly core samples. Therefore,the samples are not suitable for tests requiri
35、ng undisturbedsamples, such as hydraulic conductivity tests. In addition, soilstructures are disrupted and small scale lithologic featurescannot be examined. Nevertheless, screw-type samplers arestill suitable for use in collecting samples for the purpose ofdetecting contaminants. However, it is dif
36、ficult to avoid trans-porting shallow soils downward when reentering a drill hole.When representative samples are desired from a discreteinterval, the borehole must be made large enough to insert asampler and extend it to the bottom of the borehole withouttouching the sides of the borehole. It is su
37、ggested that a largerdiameter auger be used to advance and clear the borehole, thena smaller diameter auger sampler be used to obtain the sample.Screw-type augers work better in wet, cohesive soils than indry, loose soils. Sampling in very dry (for example, powdery)soils may not be possible with the
38、se augers as soils will not beretained on the auger flights. Also, if the soil contains gravel orrock fragments larger than about one tenth of the hole diameter,drilling may not be possible (4).7.4 Barrel Augers:7.4.1 DescriptionThe barrel auger consists of a bit withcutting edges welded to a short
39、tube or barrel within which thesoil sample is retained, welded in turn to shanks. The shanksare welded to a threaded rod at the other end. Extension rodsare attached as required to reach the target sampling depth.Extensions are marked in increments above the base of thetool. The uppermost extension
40、rod contains a tee-type couplingfor a handle. The auger is available in carbon steel and stainlesssteel with hardened steel cutting edges (5, 6).7.4.2 Sampling MethodThe auger is rotated to advancethe barrel into the ground. The operator may have to applydownward pressure to keep the auger advancing
41、. When thebarrel is filled, the unit is withdrawn from the soil cavity and asample may be collected from the barrel.7.4.3 CommentsBarrel augers generally provide largersamples than screw-type augers. The augers can penetrateshallow clays, silts, and fine grained sands (7).6The augers donot work well
42、 in gravelly soils, caliche, or semi-lithifieddeposits. Samples obtained with barrel augers are disturbedand are not core samples. Therefore, the samples are notsuitable for tests requiring undisturbed samples, such ashydraulic conductivity tests. Nevertheless, the samplers arestill suitable for use
43、 in collecting samples for the purpose ofdetecting contaminants. Because the sample is retained insidethe barrel, there is less of a chance of mixing it with soil froma shallower interval during insertion or withdrawal of thesampler. The following are five common barrel augers:7.4.3.1 Post-hole auge
44、rs (also called Iwan-type augers),7.4.3.2 Dutch-type augers,7.4.3.3 Regular or general purpose barrel augers,7.4.3.4 Sand augers, and7.4.3.5 Mud augers.7.4.4 Post-Hole AugersThe most readily available barrelauger is the post-hole auger (also called the Iwan-type auger)(8). As shown in Fig. 3, the ba
45、rrel consists of two-partcylindrical leaves rather than a complete cylinder and isslightly tapered toward the cutting bit. The taper and thecupped bit help to retain soils within the barrel. The barrel isavailable witha3to12-in. (7.62 to 30.48-cm) diameter. Thereare two types of drilling systems, on
46、e has a single rod andhandle, and the other has two handles. In stable, cohesive soils,the auger can be advanced up to 25 ft (7.62 m) (8).7.4.5 Dutch-Type AugersThe Dutch-type auger (commer-cially developed by Eijkelkamp) is a smaller variation of the6This reference is manufacturers literature, and
47、it has not been subjected totechnical review.FIG. 2 Screw Type AugersFIG. 3 Post-Hole Type Barrel AugerD 4700 91 (2006)3post-hole auger design. As shown in Fig. 4, the pointed bit iscontinuous with two, narrow part-cylindrical barrel segments,welded onto the shanks. The barrel generally hasa3in.(7.6
48、2 cm) outside diameter. This tool is best suited for sam-pling wet, clayey soils.7.4.6 Regular or General Purpose Barrel AugersA ver-sion of the barrel auger commonly used by soil scientists andcounty agricultural agents is depicted in Fig. 5(a) and (b). Asshown, the barrel is a complete cylinder. A
49、s with the post-holeauger, the cutting blades are cupped so that soil is loosened andforced into the barrel as the unit is rotated and pushed into theground. Each filling of the barrel corresponds to a depth ofpenetration of 3 to 5 in. (7.62 to 12.70 cm) (1). The mostpopular barrel diameter is 3.5 in. (8.89 cm), but sizes rangingfrom 1.5 to 7 in. (3.81 to 17.78 cm) are available (6).6Plastic,stainless steel, PTFE (polytetrafluoroethylene), or aluminumliners can also be used (6).6Extension rods are available in 4 ft(1.22 m) lengths. The rods can be made from stand
