ASTM_D_6432_-_11.pdf

Designation:D643211Standard Guide forUsing the Surface Ground Penetrating Radar Method forSubsurface Investigation1This standard is issued under the fixed designation D6432;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 Purpose and Application:1.1.1 This guide covers the equipment,field procedures,andinterpretation methods for the assessment of subsurface mate-rials using the impulse Ground Penetrating Radar(GPR)Method.GPR is most often employed as a technique that useshigh-frequency electromagnetic(EM)waves(from 10 to 3000MHz)to acquire subsurface information.GPR detects changesin EM properties(dielectric permittivity,conductivity,andmagnetic permeability),that in a geologic setting,are afunction of soil and rock material,water content,and bulkdensity.Data are normally acquired using antennas placed onthe ground surface or in boreholes.The transmitting antennaradiates EM waves that propagate in the subsurface and reflectfrom boundaries at which there are EM property contrasts.Thereceiving GPR antenna records the reflected waves over aselectable time range.The depths to the reflecting interfaces arecalculated from the arrival times in the GPR data if the EMpropagation velocity in the subsurface can be estimated ormeasured.1.1.2 GPR measurements as described in this guide are usedin geologic,engineering,hydrologic,and environmental appli-cations.The GPR method is used to map geologic conditionsthat include depth to bedrock,depth to the water table(Wrightet al(1)2),depth and thickness of soil strata on land and underfresh water bodies(Beres and Haeni(2),and the location ofsubsurface cavities and fractures in bedrock(Ulriksen(3)andImse and Levine(4).Other applications include the locationof objects such as pipes,drums,tanks,cables,and boulders,mapping landfill and trench boundaries(Benson et al(5),mapping contaminants(Cosgrave et al(6);Brewster andAnnan(7);Daniels et al(8),conducting archaeological(Vaughan(9)and forensic investigations(Davenport et al(10),inspection of brick,masonry,and concrete structures,roads and railroad trackbed studies(Ulriksen(3),and highwaybridge scour studies(Placzek and Haeni(11).Additionalapplications and case studies can be found in the variousProceedings of the International Conferences on GroundPenetrating Radar(Lucius et al(12);Hannien and Autio,(13),Redman,(14);Sato,(15);Plumb(16),various Proceedings ofthe Symposium on the Application of Geophysics to Engineer-ing and Environmental Problems(Environmental and Engi-neering Geophysical Society,19881998),and The GroundPenetrating Radar Workshop(Pilon(17),EPA(18),Daniels(19),and Jol(20)provide overviews of the GPR method.1.1.3 The geotechnical industry uses English or SI units.1.2 Limitations:1.2.1 This guide provides an overview of the impulse GPRmethod.It does not address details of the theory,fieldprocedures,or interpretation of the data.References are in-cluded for that purpose and are considered an essential part ofthis guide.It is recommended that the user of the GPR methodbe familiar with the relevant material within this guide and thereferences cited in the text and with Guides D420,D5730,D5753,D6429,and D6235.1.2.2 This guide is limited to the commonly used approachto GPR measurements from the ground surface.The methodcan be adapted for a number of special uses on ice(Haeni et al(21);Wright et al(22),within or between boreholes(Lane etal(23);Lane et al(24),on water(Haeni(25),and airborne(Arcone et al(25)applications.A discussion of these otheradaptations of GPR measurements is not included in this guide.1.2.3 The approaches suggested in this guide for using GPRare the most commonly used,widely accepted,and proven;however,other approaches or modifications to using GPR thatare technically sound may be substituted if technically justifiedand documented.1.2.4 This guide offers an organized collection of informa-tion or a series 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 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 many1This guide is under the jurisdiction of ASTM CommitteeD18 on Soil and Rockand is the direct responsibility of Subcommittee D18.01 on Surface and SubsurfaceCharacterization.Current edition approved May 1,2011.Published June 2011.Originallyapproved in 1999.Last previous edition approved in 2005 as D6432 99(2005).DOI:10.1520/D6432-11.2The boldface numbers in parentheses refer to the list of refere