1、Designation: D 6429 99 (Reapproved 2006)Standard Guide forSelecting Surface Geophysical Methods1This standard is issued under the fixed designation D 6429; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、A number 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 the selection of surface geophysicalmethods, as commonly applied to geologic, geotechnical,hydrologic, and environ
3、mental 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 for each surface geophysicalmethod.1.2 Surface g
4、eophysical 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 hydrologic,geologic, geotechnical, and hazardous was
5、te 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. Numerousreferences are included for that purpose and
6、 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 D 420, D 5730, D 5753, D 5777, and D 6285, as wellas Practices D 5088, D 5608, D 6235, and Test Method G57.1.5 To obtain detailed information on sp
7、ecific 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) responsible for planning, carryingout the s
8、urvey, 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 should be cautious about usinggeophysi
9、cal 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 series of options and does not recommend
10、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 replace the standard of care by which
11、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 consensus process.1.9 This standard d
12、oes 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 use.2. Referenced Documents2.1 ASTM St
13、andards:3D 420 Guide to Site Characterization for Engineering De-sign and Construction PurposesD 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 4428/D 4428M Test Methods for Crosshole Seismic Test-ingD 5088 Practices for Decontamination of Field EquipmentUsed at Waste SitesD 5608 Pract
14、ices for Decontamination of Field EquipmentUsed at Low Level Radioactive Waste SitesD 5730 Guide for Site Characterization for EnvironmentalPurposes With Emphasis on Soil, Rock, the Vadose Zoneand Ground WaterD 5753 Guide for Planning and Conducting Borehole Geo-physical LoggingD 5777 Guide for Usin
15、g the Seismic Refraction Method for1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.01 on Surface and SubsurfaceCharacterization.Current edition approved March 15, 2006. Published May 2006. Originallyapproved in 1999. Las
16、t previous edition approved in 1999 as D 642999.2The boldface numbers given in parentheses refer to a list of references at theend 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 ASTMStandar
17、ds volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Subsurface InvestigationD 6235 Practice for Expedited Site Characterization ofVadose Zone and Grou
18、nd Water Contamination at Hazard-ous Waste Contaminated SitesD 6285 Guide for Locating Abandoned WellsG57 Test Method for Field Measurement of Soil ResistivityUsing the Wenner Four-Electrode Method3. Terminology3.1 DefinitionsDefinitions shall be in accordance with theterms and symbols given in Term
19、inology D 653. Also see Ref(1) for specific geophysical terms and definitions.4. Summary of Guide4.1 This guide applies to surface geophysical techniquesthat are commonly used in site characterization, as well asforensic and archaeological applications.4.2 The selection of preferred geophysical meth
20、ods 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 alongwith some of the field considerations and limitations also areprovided.4.4 It is recommended that personnel consult
21、appropriatereferences on each of the methods, applications, and theirinterpretations. All geophysical measurements should be car-ried out by knowledgeable professionals who have experienceand training in theory and application of the method, and theinterpretation of the data resulting from the use o
22、f 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 Table 1 is based upon the ability of each methodto produce results under average field conditions when com-pared to othe
23、r 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 can be applied with equal success. There may alsobe a method or methods that will be successful technically at alower co
24、st. The final selection must be made considering sitespecific conditions and project objectives; therefore, it iscritical to have an experienced professional make the finaldecision as to the method(s) selected.5.1.1 Benson (2) provides one of the earlier guides to theapplication of geophysics to env
25、ironmental problems.5.1.2 Ward (3) is a three-volume compendium that dealswith geophysical methods applied to geotechnical and envi-ronmental problems.5.1.3 Olhoeft (4) provides an expert system for helpingselect geophysical methods to be used at hazardous waste sites.TABLE 1 Selection of Geophysica
26、l Methods for Common ApplicationsA,BGeophysical MethodsApplicationsSeismic Electrical ElectromagneticRefraction(6.1)Reflection(6.2)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)Nat
27、ural 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 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
28、BInorganic ContaminantsLandfill leachate A A A B BSaltwater intrusion A A A B BSoil salinity A AOrganic ContaminantsLight, nonaqueous 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
29、 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.B“B” implies secondary choice or alternate method.CAlso see natural geologic and hydrologic conditions to characterize contaminant pathways.D 6429 99 (2006)25.1.4 EPA (5) p
30、rovides 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 factor affecting the accuracy of geotechni-cal or environmental site characterization efforts is the numberof sample points
31、or borings. Insufficient spatial sampling toadequately characterize the conditions at a site can result if thenumber of samples is too small. Interpolation between thesesample points may be difficult and may lead to an inaccuratesite characterization. Benson (2) provides an assessment of theprobabil
32、ity 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 interpolation between known points of control.Continuous data acquisition can be obtained with certaingeophysical methods at sp
33、eeds 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 background (ambient) conditions and detectanomalous conditions resulting in a more accurate site charac-terization than using
34、 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 conditions, orboth.5.3 A contrast must be present for geophysical measure-ments to be successful.5.3.1 Geophysical methods mea
35、sure 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 buried drum, there must be a contrast in theproperty being measured, for example, the target to be detectedor geologic feature
36、 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 detected by the differences inelectrical properties of the pore fluids. The contact between soiland unweathered bedrock can
37、 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 geophysical methods.5.3.3 Because physical properties of soil and rock varywidely, some by many orders of magnitude, one or m
38、ore ofthese properties usually will correspond to a geologic discon-tinuity; therefore, boundaries determined by the geophysicalmethods will usually coincide with geological boundaries, anda cross-section produced from the geophysical data mayresemble a geological cross-section, although the two are
39、 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 contaminant plumes; and,5.4.3 Locating and mapping buried objects.5.5 Geophysical methods should be used in the followinginstances
40、: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 thatboring and sampling points can be located to be representativeof site conditions and to investigate anomalies. Geophysi
41、calmethods 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-indata between other measurements.5.5.2 The level of success of a geophysical survey isimproved if the survey objectives
42、 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 approach should be built into theprogram to account for changes in interpretation of siteconditions as a site investigat
43、ion progresses.5.6 Profiling and Sounding Measurements:5.6.1 Profiling by stations or by continuous measurementsprovides a means of assessing lateral changes in subsurfaceconditions.5.6.2 Soundings provide a means of assessing depth andthickness of geologic layers or other targets. Most surfacegeoph
44、ysical 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, in application, geophysical methods often yieldinterpretations that are qualitative.5.7.2 Some geophysical methods provide
45、 data from which apreliminary interpretation can be made in the field, for ex-ample, ground penetrating radar (GPR), frequency domainelectromagnetic profiling, direct current (DC) resistivity pro-filing, magnetic profiling, and metal detector profiling. A mapof GPR anomalies or a contour map of the
46、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 resistivity soundings, seismic refraction,seismic reflection, and gravity), require that the data beprocessed before any quantit
47、ative 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 other information from knownpoints of control, such as borings or outcrops. Such preliminaryanalysis is subject to chang
48、e 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 for site characterization. Theconversion of raw data to useful information is a value-addedprocess that experienced prof
49、essionals 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:5.8.1 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 orD 6429 99 (2006)3include lenses of various materials. These layers can bedetected because of differences in their physical properties ascompar
