1、Designation: D7128 18Standard Guide forUsing the Seismic-Reflection Method for ShallowSubsurface Investigation1This standard is issued under the fixed designation D7128; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 Purpose and Application:1.1.1 This guide summarizes the technique, equipment, fieldprocedures, data processing, and int
3、erpretation methods for theassessment of shallow subsurface conditions using the seismic-reflection method.1.1.2 Seismic reflection measurements as described in thisguide are applicable in mapping shallow subsurface conditionsfor various uses including geologic (1), geotechnical, hydro-geologic (2),
4、 and environmental (3).2The seismic-reflectionmethod is used to map, detect, and delineate geologic condi-tions including the bedrock surface, confining layers(aquitards), faults, lithologic stratigraphy, voids, water table,fracture systems, and layer geometry (folds). The primaryapplication of the
5、seismic-reflection method is the mapping oflateral continuity of lithologic units and, in general, detectionof change in acoustic properties in the subsurface.1.1.3 This guide will focus on the seismic-reflection methodas it is applied to the near surface. Near-surface seismicreflection applications
6、 are based on the same principles asthose used for deeper seismic reflection surveying, but ac-cepted practices can differ in several respects. Near-surfaceseismic-reflection data are generally high-resolution (dominantfrequency above 80 Hz) and image depths from around6mtoas much as several hundred
7、 meters. Investigations shallowerthan 6 m have occasionally been undertaken, but these shouldbe considered experimental.1.2 Limitations:1.2.1 This guide provides an overview of the shallowseismic-reflection method, but it does not address the details ofseismic theory, field procedures, data processi
8、ng, or interpre-tation of the data. Numerous references are included for thatpurpose and are considered an essential part of this guide. It isrecommended that the user of the seismic-reflection method befamiliar with the relevant material in this guide, the referencescited in the text, and Guides D4
9、20, D653, D2845, D4428/D4428M, Practice D5088, Guides D5608, D5730, D5753,D6235, and D6429.1.2.2 This guide is limited to two-dimensional (2-D) shal-low seismic-reflection measurements made on land. Theseismic-reflection method can be adapted for a wide variety ofspecial uses: on land, within a bore
10、hole, on water, and in threedimensions (3-D). However, a discussion of these specializedadaptations of reflection measurements is not included in thisguide.1.2.3 This guide provides information to help understandthe concepts and application of the seismic-reflection methodto a wide range of geotechn
11、ical, engineering, and groundwaterproblems.1.2.4 The approaches suggested in this guide for theseismic-reflection method are commonly used, widelyaccepted, and proven; however, other approaches or modifica-tions to the seismic-reflection method that are technicallysound may be equally suited.1.2.5 T
12、echnical limitations of the seismic-reflection methodare discussed in 5.4.1.2.6 This guide discusses both compressional (P) and shear(S) wave reflection methods. Where applicable, the distinctionsbetween the two methods will be pointed out in this guide.1.3 This guide offers an organized collection
13、of informationor 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 guide is not intended to
14、represent orreplace the standard of care by which the adequacy of a givenprofessional service must be judged, nor should this documentbe applied without consideration for a projects many uniqueaspects. The word “Standard” in the title of this guide meansonly that the document has been approved throu
15、gh the ASTMconsensus process.1.4 The values stated in SI units are regarded as standard.The values given in parentheses are inch-pound units, whichare provided for information only and are not consideredstandard.1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the di
16、rect responsibility of Subcommittee D18.01 on Surface and SubsurfaceCharacterization.Current edition approved July 15, 2018. Published August 2018. Originallyapproved in 2005. Last previous edition approved in 2010 as D712805(2010).DOI: 10.1520/D7128-18.2The boldface numbers in parentheses refer to
17、the list of references at the end ofthis standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the
18、Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.11.5 Precautions:1.5.1 It is the responsibility of the user of this guide tofollow any precautions within the equipment
19、manufacturersrecommendations, establish appropriate health and safetypractices, and consider the safety and regulatory implicationswhen explosives or any high-energy (mechanical or chemical)sources are used.1.5.2 If the method is applied at sites with hazardousmaterials, operations, or equipment, it
20、 is the responsibility ofthe user of this guide to establish appropriate safety and healthpractices and determine the applicability of any regulationsprior to use.1.5.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of th
21、e user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization establishe
22、d in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3D420 Guide for Site Characterization for Engineering De-sign and Con
23、struction PurposesD653 Terminology Relating to Soil, Rock, and ContainedFluidsD2845 Test Method for Laboratory Determination of PulseVelocities and Ultrasonic Elastic Constants of Rock(Withdrawn 2017)4D3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil an
24、d Rock asUsed in Engineering Design and ConstructionD4428/D4428M Test Methods for Crosshole Seismic Test-ingD5088 Practice for Decontamination of Field EquipmentUsed at Waste SitesD5608 Practices for Decontamination of Sampling and NonSample Contacting Equipment Used at Low Level Radio-active Waste
25、SitesD5730 Guide for Site Characterization for EnvironmentalPurposes With Emphasis on Soil, Rock, the Vadose Zoneand Groundwater (Withdrawn 2013)4D5753 Guide for Planning and Conducting GeotechnicalBorehole Geophysical LoggingD5777 Guide for Using the Seismic Refraction Method forSubsurface Investig
26、ationD6235 Practice for Expedited Site Characterization of Va-dose Zone and Groundwater Contamination at HazardousWaste Contaminated SitesD6429 Guide for Selecting Surface Geophysical MethodsD6432 Guide for Using the Surface Ground PenetratingRadar Method for Subsurface Investigation3. Terminology3.
27、1 Definitions:3.1.1 For definitions of common technical terms used in thisstandard, refer to Terminology D653.3.2 Definitions Specific to This Guide3.2.1 acoustic impedance, nproduct of seismic compres-sional wave velocity and density. Compressional wave velocityof a material is dictated by its bulk
28、 modulus, shear modulus,and density. Seismic impedance is the more general term forthe product of seismic velocity and density.3.2.2 automatic gain control (AGC), ntrace amplitudeadjustment that varies as a function of time and the amplitudeof adjacent data points. Amplitude adjustment changing theo
29、utput amplitude so that at least one sample is at full scaledeflection within a selected moving window (moving in time).3.2.3 blind seismic deconvolution, na very challengingand yet common seismic deconvolution problem is where thesource wave is unknown and has the potential for timevariation. Ident
30、ifies the case where we have one known(measured seismogram with additive noise) and two unknowns(source wave and reflection coefficients).3.2.4 body waves, nP- and S-waves that travel through thebody of a medium, as opposed to surface waves which travelalong the surface of a half-space.3.2.5 bulk mo
31、dulus, nthe resistance of a material tochange its volume in response to the hydrostatic load. Bulkmodulus (K) is also known as the modulus of compression.3.2.6 check shot survey (downhole survey), ndirect mea-surement of traveltime between the surface and a given depth.Usually sources on the surface
32、 are recorded by a seismicreceiver in a well to determine the time-to-depth relationshipsat a specified location.3.2.7 coded source, na seismic energy-producing devicethat delivers energy throughout a given time in a predeterminedor predicted fashion.3.2.8 common mid-point (CMP) or common depth poin
33、t(CDP) method, na recording-processing method in whicheach source is recorded at a number of locations and eachlocation is used to record from a number of source locations.3.2.8.1 DiscussionAfter corrections, these data traces arethen combined (stacked) to provide a common-midpoint sec-tion approxim
34、ating a coincident source and receiver at eachlocation. The objective is to attenuate random effects andevents whose dependence on offset is different from that ofprimary reflections.3.2.9 compressional wave velocity (P-wave velocity), nthepropagation rate of a seismic wave without implying anydirec
35、tion, that is, velocity is a property of the medium. Particledisplacement of a compressional wave is in the direction ofpropagation.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inform
36、ation, refer to the standards Document Summary page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.D7128 1823.2.10 dynamic range, nthe ratio of the maximum readingto the minimum reading which can be recorded by and readfrom an instrument withou
37、t change of scale.3.2.11 fold (redundancy), nthe multiplicity of common-midpoint data or the number of midpoints per bin.3.2.11.1 DiscussionWhere the midpoint is the same for 12source/receiver pairs, the stack is referred to as “12-fold” or1200 percent.3.2.12 G-force, nmeasure of acceleration relati
38、ve to thegravitational force of the earth.3.2.13 impedance contrast, nratio of the seismic imped-ance across a boundary or seismic impedance of the lowerlayer divided by the seismic impedance of the upper layer.3.2.13.1 DiscussionA value of 1 implies total transmit-tance. Values increase or decrease
39、 from 1 as the contrastincreases, that is, more energy reflection from a boundary.Values less than 1 are indicative of a negative reflectivity orreversed reflection wavelet polarity.3.2.14 normal moveout (NMO), nthe difference inreflection-arrival time as a function of shot-to-receiver distancebecau
40、se the receiver is not located at the source point.3.2.14.1 DiscussionIt is the additional traveltime requiredbecause of offset, assuming that the reflecting bed is notdipping and that raypaths are straight lines. This leads to ahyperbolic shape for a reflection.3.2.15 normal moveout velocity (stack
41、ing velocity),nvelocity to a given reflector calculated from normal-moveout measurements, assuming a constant-velocity model.3.2.15.1 DiscussionBecause the raypath actually curvesas the velocity changes, fitting a hyperbola assumes that theactual velocity distribution is equivalent to a constant NMO
42、velocity, but the NMO velocity changes with the offset.However, the assumption often provides an adequate solutionfor offsets less than the reflector depth. Used to calculate NMOcorrections to common-midpoint gathers prior to stacking.3.2.16 Nyquist frequency, nalso known as the aliasing orfolding f
43、requency, is equal to half the sampling frequency orrate.3.2.17 optimum window, nrange of offsets between sourceand receiver that provide reflections with the best signal-to-noise ratio.3.2.18 raypath, na line everywhere perpendicular towavefronts (in isotropic media).3.2.19 reflection, nthe energy
44、or wave from a seismicsource that has been reflected (returned) from an acoustic-impedance contrast (reflector) or series of contrasts within theearth.3.2.20 reflection series, nthe reflection coefficients defin-ing a stratigaphic profile.3.2.21 reflector, nan interface having a contrast in physi-ca
45、l properties (elasticity and/or density) that reflects seismicenergy.3.2.22 roll-along switch, na switch that connects differentgeophone groups to the recording instruments, used incommon-midpoint recording.3.2.23 seismic convolution, nthe convolution between thereflection series and source wave.3.2
46、.24 seismic deconvolution, nthe process of removingthe characteristics of the source wave from the recordedseismic time series so that one is ideally left with only thereflection coefficients.3.2.25 seismic impedance, nproduct of seismic wave ve-locity and density.3.2.25.1 Discussion The seismic imp
47、edance includesshear waves and surface waves, whereas acoustic impedance,by strict definition, includes only compressional waves.3.2.26 seismic sensor, nreceivers designed to couple to theearth and record vibrations (for example, geophones,accelerometers, hydrophones).3.2.27 seismic sensor group (sp
48、read), nmultiple receiversconnected to a single recording channel, generally deployed inan array designed to enhance or attenuate specific energy.3.2.28 shear modulus (G) (rigidity modulus), nthe ratio ofshear stress to shear strain of a material as a result of loading3.2.28.1 DiscussionG is equival
49、ent to the second Lamconstant. For small deformations, Hookes law holds and strainis proportional to stress.3.2.29 shear wave velocity (S-wave velocity), nspeed ofenergy traveling with particle motion perpendicular to itsdirection of propagation.3.2.30 shot gather (field files), na side-by-side display ofseismic traces that have a common source location.3.2.31 source to seismic sensor offset, nthe distance fromthe source-point to the seismic sensor or to the center of aseismic sensor (group) spread.3.2.32 source wave, nseismic source wave ge
