1、Designation: D6429 99 (Reapproved 2011)1Standard Guide forSelecting Surface Geophysical Methods1This standard is issued under the fixed designation D6429; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEEditorially revised Section 3 in July 2011.1. Scope1.1 This guide covers the selection of surface geophysicalmethods, as commonly applied to
3、geologic, geotechnical,hydrologic, and environmental investigations (hereafter re-ferred to as site characterization), as well as forensic andarchaeological applications. This guide does not describe thespecific procedures for conducting geophysical surveys. Indi-vidual guides are being developed fo
4、r each surface geophysicalmethod.1.2 Surface geophysical methods yield direct and indirectmeasurements of the physical properties of soil and rock andpore fluids, as well as buried objects.1.3 The geophysical methods presented in this guide areregularly used and have been proven effective for hydrol
5、ogic,geologic, geotechnical, and hazardous waste site assessments.1.4 This guide provides an overview of applications forwhich surface geophysical methods are appropriate. It does notaddress the details of the theory underlying specific methods,field procedures, or interpretation of the data. Numero
6、usreferences are included for that purpose and are considered anessential part of this guide. It is recommended that the user ofthis guide be familiar with the references cited (1-20)2and withGuides D420, D5730, D5753, D5777, and D6285, as well asPractices D5088, D5608, D6235, and Test Method G57.1.
7、5 To obtain detailed information on specific geophysicalmethods, ASTM standards, other publications, and referencescited in this guide, should be consulted.1.6 The success of a geophysical survey is dependent uponmany factors. One of the most important factors is thecompetence of the person(s) respo
8、nsible for planning, carryingout the survey, and interpreting the data. An understanding ofthe methods theory, field procedures, and interpretation alongwith an understanding of the site geology, is necessary tosuccessfully complete a survey. Personnel not having special-ized training or experience
9、should be cautious about usinggeophysical methods and should solicit assistance from quali-fied practitioners.1.7 The values stated in SI units are to be regarded as theguide. The values given in parentheses are for informationonly.1.8 This guide offers an organized collection of informationor a ser
10、ies of options and does not recommend a specificcourse of action. This document cannot replace education orexperience 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
11、replace the standard of care by which the adequacy ofa given professional service must be judged, nor should thisdocument 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
12、 consensus process.1.9 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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to
13、use.2. Referenced Documents2.1 ASTM Standards:3D420 Guide to Site Characterization for Engineering De-sign and Construction PurposesD653 Terminology Relating to Soil, Rock, and ContainedFluidsD4428/D4428M Test Methods for Crosshole Seismic Test-ingD5088 Practice for Decontamination of Field Equipmen
14、tUsed at Waste SitesD5608 Practices for Decontamination of Field EquipmentUsed at Low Level Radioactive Waste SitesD5730 Guide for Site Characterization for Environmental1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.01
15、 on Surface and SubsurfaceCharacterization.Current edition approved July 1, 2011. Published September 2011. Originallyapproved in 1999. Last previous edition approved in 2006 as D642999(2006).DOI: 10.1520/D6429-99R11e1.2The boldface numbers given in parentheses refer to a list of references at theen
16、d of this standard.3For 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.1Copyright ASTM International, 100 Barr Ha
17、rbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Purposes With Emphasis on Soil, Rock, the Vadose Zoneand Ground WaterD5753 Guide for Planning and Conducting Borehole Geo-physical LoggingD5777 Guide for Using the Seismic Refraction Method forSubsurface InvestigationD6235 Prac
18、tice for Expedited Site Characterization of Va-dose Zone and Ground Water Contamination at HazardousWaste Contaminated SitesD6285 Guide for Locating Abandoned WellsG57 Test Method for Field Measurement of Soil ResistivityUsing the Wenner Four-Electrode Method3. Terminology3.1 Definitions:3.1.1 Defin
19、itions shall be in accordance with the terms andsymbols given in Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 See Ref (1) for specific geophysical terms and defini-tions.4. Summary of Guide4.1 This guide applies to surface geophysical techniquesthat are commonly used in
20、site characterization, as well asforensic and archaeological applications.4.2 The selection of preferred geophysical methods for anumber of common applications is summarized in Table 1. Thetable is followed by brief descriptions of each application.4.3 A brief description of each geophysical method
21、alongwith some of the field considerations and limitations also areprovided.4.4 It is recommended that personnel consult appropriatereferences on each of the methods, applications, and theirinterpretations. All geophysical measurements should be car-ried out by knowledgeable professionals who have e
22、xperienceand training in theory and application of the method, and theinterpretation of the data resulting from the use of the specificmethod.5. Significance and Use5.1 This guide applies to commonly used surface geophysi-cal methods for those applications listed in Table 1. The ratingsystem used in
23、 Table 1 is based upon the ability of each methodto produce results under average field conditions when com-pared to other methods applied to the same application.An “A”rating implies a preferred method and a “B” rating implies analternate method. There may be a single method or multiplemethods that
24、 can be applied with equal success. There may alsobe a method or methods that will be successful technically at alower cost. The final selection must be made considering sitespecific conditions and project objectives; therefore, it iscritical to have an experienced professional make the finaldecisio
25、n as to the method(s) selected.5.1.1 Benson (2) provides one of the earlier guides to theapplication of geophysics to environmental problems.TABLE 1 Selection of Geophysical Methods for Common ApplicationsA,BGeophysical MethodsApplicationsSeismic Electrical ElectromagneticRefraction(6.1)Reflection(6
26、.2)DCResistivity(6.3)SP(6.4)FrequencyDomain(6.5)TimeDomain(6.6)VLF (6.7)Pipe/CableLocator(6.8)MetalDetectors(6.9)GroundPenetratingRadar(6.10)Magnetics(6.11)Gravity(6.12)Natural Geologic and HydrologicConditionsSoil/unconsolidated layers A B A B A B ARock layers B A B B BDepth to bedrock A A B B B B
27、A BDepth to water table A A B B B B AFractures and fault zones B B B A B A B B BVoids and sinkholes B B B B B A ASoil and rock properties A A BDam and lagoon leakage B A B BInorganic ContaminantsLandfill leachate A A A B BSaltwater intrusion A A A B BSoil salinity A AOrganic ContaminantsLight, nonaq
28、ueous phase liquids B B B BDissolved phaseCDense, nonaqueous phaseliquidsCManmade Buried ObjectsUtilities BABADrums and USTs A A A A AUXO ABAAbandoned wells B B B ALandfill and trench boundaries B B A B AForensics B A B B A BArchaeological features B B B A A A BA“A” implies primary choice of method.
29、B“B” implies secondary choice or alternate method.CAlso see natural geologic and hydrologic conditions to characterize contaminant pathways.D6429 99 (2011)125.1.2 Ward (3) is a three-volume compendium that dealswith geophysical methods applied to geotechnical and envi-ronmental problems.5.1.3 Olhoef
30、t (4) provides an expert system for helpingselect geophysical methods to be used at hazardous waste sites.5.1.4 EPA (5) provides an excellent literature review of thetheory and use of geophysical methods for use at contaminatedsites.5.2 An Introduction to Geophysical Measurements:5.2.1 A primary fac
31、tor affecting the accuracy of geotechni-cal or environmental site characterization efforts is the numberof sample points or borings. Insufficient spatial sampling toadequately characterize the conditions at a site can result if thenumber of samples is too small. Interpolation between thesesample poi
32、nts may be difficult and may lead to an inaccuratesite characterization. Benson (2) provides an assessment of theprobability of target detection using only borings.5.2.2 Surface and borehole geophysical measurements gen-erally can be made relatively quickly, are minimally intrusive,and enable interp
33、olation between known points of control.Continuous data acquisition can be obtained with certaingeophysical methods at speeds up to several km/h. In somecases, total site coverage is economically possible. Because ofthe greater sample density, the use of geophysical methods canbe used to define back
34、ground (ambient) conditions and detectanomalous conditions resulting in a more accurate site charac-terization than using borings alone.5.2.3 Geophysical measurements provide a means of map-ping lateral and vertical variations of one or more physicalproperties or monitoring temporal changes in condi
35、tions, orboth.5.3 A contrast must be present for geophysical measure-ments to be successful.5.3.1 Geophysical methods measure the physical, electrical,or chemical properties of soil, rock, and pore fluids. To detectan anomaly, a soil to rock contact, the presence of inorganiccontaminants, or a burie
36、d drum, there must be a contrast in theproperty being measured, for example, the target to be detectedor geologic feature to be defined must have properties signifi-cantly different from “background” conditions.5.3.2 For example, the interface between fresh water andsaltwater in an aquifer can be de
37、tected by the differences inelectrical properties of the pore fluids. The contact between soiland unweathered bedrock can be detected by the differences inacoustic velocity of the materials. In some cases, the differ-ences in measured physical properties may be too small foranomaly detection by geop
38、hysical methods.5.3.3 Because physical properties of soil and rock varywidely, some by many orders of magnitude, one or more ofthese properties usually will correspond to a geologic discon-tinuity; therefore, boundaries determined by the geophysicalmethods will usually coincide with geological bound
39、aries, anda cross-section produced from the geophysical data mayresemble a geological cross-section, although the two are notnecessarily identical.5.4 Geophysical methods commonly are used for the fol-lowing reasons:5.4.1 Mapping natural hydrogeologic conditions;5.4.2 Detecting and mapping contamina
40、nt plumes; and,5.4.3 Locating and mapping buried objects.5.5 Geophysical methods should be used in the followinginstances:5.5.1 Surface geophysical methods can and should be usedearly in a site characterization program to aid in identifyingbackground conditions, as well as anomalous conditions so th
41、atboring and sampling points can be located to be representativeof site conditions and to investigate anomalies. Geophysicalmethods also can be used later in the site characterizationprogram after an initial study is completed to confirm andimprove the site characterization findings and provide fill
42、-indata between other measurements.5.5.2 The level of success of a geophysical survey isimproved if the survey objectives are well defined. In somecases, the objective may be refined as the survey uncovers newor unknown data about the site conditions. The flexibility tochange or add to the technical
43、 approach should be built into theprogram to account for changes in interpretation of siteconditions as a site investigation progresses.5.6 Profiling and Sounding Measurements:5.6.1 Profiling by stations or by continuous measurementsprovides a means of assessing lateral changes in subsurfaceconditio
44、ns.5.6.2 Soundings provide a means of assessing depth andthickness of geologic layers or other targets. Most surfacegeophysical sounding measurements can resolve three andpossibly four layers.5.7 Ease of Use and Interpretation of Data:5.7.1 The theory of applied geophysics is quantitative,however, i
45、n application, geophysical methods often yieldinterpretations that are qualitative.5.7.2 Some geophysical methods provide data from which apreliminary interpretation can be made in the field, for ex-ample, ground penetrating radar (GPR), frequency domainelectromagnetic profiling, direct current (DC)
46、 resistivity pro-filing, magnetic profiling, and metal detector profiling. A mapof GPR anomalies or a contour map of the EM (electromag-netic), resistivity, magnetic or metal detector data often can becreated in the field.5.7.3 Some methods, (for example, time domain electro-magnetics and DC resisti
47、vity soundings, seismic refraction,seismic reflection, and gravity), require that the data beprocessed before any quantitative interpretation can be done.5.7.4 Any preliminary interpretation of field data should betreated with caution. Such preliminary analysis should beconfirmed by correlation with
48、 other information from knownpoints of control, such as borings or outcrops. Such preliminaryanalysis is subject to change after data processing and isperformed mostly as a means of quality control (QC).5.7.5 It is the interpretation and integration of all site datathat results in useful information
49、 for site characterization. Theconversion of raw data to useful information is a value-addedprocess that experienced professionals achieve by carefulanalysis. Such analysis must be conducted by a competentprofessional to ensure that the interpretation is consistent withgeologic and hydrologic conditions.5.8 Discussion of Applications:D6429 99 (2011)135.8.1 Natural Geologic and Hydrologic Conditions:5.8.1.1 Soil/Unconsolidated LayersThis application in-cludes determining the depth to, thickness of, and areal extentof unconsolidated layers. These layers may be discontinuous o
