1、Designation: D4452 06D4452 14Standard Practice forX-Ray Radiography of Soil Samples1This standard is issued under the fixed designation D4452; 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 p
2、arentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers the determination of the quality of soil samples in thin wall tubes or of extruded cores by X-rayradiography.1.2 This practi
3、ce enables the user to determine the effects of sampling and natural variations within samples as identified by theextent of the relative penetration of X-rays through soil samples.1.3 This practice can be used to X-ray cores (or observe their features on a fluoroscope) in thin wall tubes or liners
4、ranging fromapproximately 2 to 6 in. (51 to 152 mm)50 to 150 mm (2 to 6 in.) in diameter. X-rays of samples in the larger diameter tubesprovide a radiograph of major features of soils and disturbances, such as large scale bending of edges of varved clays, shear planes,the presence of large concretio
5、ns, silt and sand seams thicker than 1/4 in. (6.46 mm (14 mm),in.), large lumps of organic matter,and voids or other types of intrusions. X-rays of the smaller diameter cores provide higher resolution of soil features anddisturbances, such as small concretions (1/8 in. (3.2(3 mm (18 mm)in.) diameter
6、 or larger), solution channels, slight bending ofedges of varved clays, thin silt or sand seams, narrow solution channels, plant root structures, and organic matter. The X-rayingof samples in thin wall tubes or liners requires minimal preparationpreparation.1.4 Greater detail and resolution of vario
7、us features of the soil can be obtained by X-raying of extruded cores, as compared tosamples in metal tubes. The method used for X-raying cores is the same as that for tubes and liners, except that extruded coreshave to be handled with extreme care and have to be placed in sample holders (similar to
8、 Fig. 2) before X-raying. This practiceshould be used only when natural moisture water content or other undisturbedintact soil characteristics are irrelevant to the enduse of the sample.1.4.1 Often it is necessary to obtain greater resolution of features to determine the propriety of sampling method
9、s, therepresentative nature of soil samples, or anomalies in soils. This practice requires that either duplicate samples be obtained oralready tested specimens be X-rayed.1.5 This practice can only be used to their fullest extent after considerable experience is obtained through many detailedcompari
10、sons between the X-ray filmimage and the sample X-rayed.1.6 UnitsThe values stated in inch-poundSI units are to be regarded as the standard. The SI values given in parentheses aremathematical conversions to inch-pound units, which are provided for information purposes only. only and are not consider
11、edstandard.1.6.1 Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method.1.7 This practice offers a set of instructions for performing one or more specific operations. This document cannot replaceeducation or experience and should be used in con
12、junction with professional judgment. Not all aspects of this practice may beapplicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which theadequacy of a given professional service must be judged, nor should this document be applied withou
13、t consideration of a projectsmany unique aspects. The word “Standard” in the title of this document means only that the document has been approved throughthe ASTM consensus process.1.8 All observed and calculated values shall conform to the guidelines for significant digits and rounding established
14、in PracticeD6026.1.8.1 For purposes of comparing, a measured or calculated value(s) with specified limits, the measured or calculated value(s)shall be rounded to the nearest decimal or significant digits in the specified limits.1 This practice is under the jurisdiction of ASTM Committee D18 on Soil
15、and Rock and are the direct responsibility of Subcommittee D18.07 on Identification andClassification of Soils.Current edition approved Nov. 1, 2006July 1, 2014. Published January 2007August 2014. Originally approved in 1985. Last previous edition approved in 20022006 asD4452 85 (2002)06. 1. DOI: 10
16、.1520/D4452-06.10.1520/D4452-14.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recomme
17、nds that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700,
18、 West Conshohocken, PA 19428-2959. United States11.8.2 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industrystandard. In addition, they are representative of the signification digits that generally should be retained. The procedur
19、es used donot consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the usersobjectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with theseconsiderations. It is beyond the scope o
20、f this standard to consider significant digits used in analysis methods for engineering design.1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health pr
21、actices and determine the applicability of regulatorylimitations prior to use. For specific precaution statements, see Section 6.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and Contained FluidsD3740 Practice for Minimum Requirements for Agencies Engaged in Tes
22、ting and/or Inspection of Soil and Rock as Used inEngineering Design and ConstructionD6026 Practice for Using Significant Digits in Geotechnical DataE7 Terminology Relating to Metallography3. Terminology3.1 Definitions:3.1.1 For definitions of terms relating to soil samples, refer to Terminology D65
23、3.3.1.2 For definitions of terms relating to X rays, refer to Definitions E7.4. Significance and Use4.1 Many geotechnical tests require the utilization of undisturbed,intact, representative samples of soil deposits. The quality ofthese samples depends on many factors. Many of the samples obtained by
24、 undisturbedintact sampling methods have inherentanomalies. Sampling procedures cause disturbances of varying types and intensities. These anomalies and disturbances, however,are not always readily detectable by visual inspection of the undisturbedintact samples before or after testing. Often test r
25、esultswould be enhanced if the presence and the extent of these anomalies and disturbances are known before testing or beforedestruction of the sample by testing. Such determinations assist the user in detecting flaws in sampling methods, the presence ofnatural or induced shear planes, and the prese
26、nce of natural intrusions, such as gravels or shells at critical regions in the samples,the presence of sand and silt seams, and the intensity of some of the unavoidable disturbances caused by sampling.4.2 X-ray radiography provides the user with a picture of the internal massive structure of the so
27、il sample, regardless of whetherthe soil is X-rayed within or without the sampling tube. X-ray radiography assists the user in identifying the following:4.2.1 Appropriateness of sampling methods used,4.2.2 Effects of sampling in terms of the disturbances caused by the turning of the edges of various
28、 thin layers in varved soils,large disturbances caused in soft soils, shear planes induced by sampling, or extrusion, or both, effects of overdriving of samplers,the presence of cuttings in sampling tubes, or the effects of using bent, corroded, or nonstandard tubes for sampling,4.2.3 Naturally occu
29、rring fissures, shear planes, and the like,4.2.4 The presence of intrusions within the sample, such as calcareous nodules, gravel, or shells, and4.2.5 Sand and silt seams, organic matter, large voids, and channels developed by natural or artificial leaching of soilscomponents.NOTE 1The quality of th
30、e results produced by this standard is dependent on the competence of the personnel performing it, and the suitability of theequipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally cojsideredconsidered capable of competent and objectivetesting/sampling/inspecti
31、on/and the like. Users of this method are cautioned that compliance with Practice D3740 does not in itself assureensure reliabletesting. Reliable testing depedsdepends on many factors; Practice D3740 provides a means of evaluating some of those factors.5. Apparatus5.1 X-Ray Radiography EquipmentEqui
32、pment with a peak current of approximately 15 mA is needed for a wide range ofapplications capable of accommodating commercially available film or detector plates, suitable for the sample sizes to be X-rayed,and suitable for the sample holders. The equipment may be equipped with a fluoroscope.5.2 X-
33、Ray Radiography EquipmentTheAlthough equipment shall have a minimum output voltage of 100 kV. Equipment witha peak current of approximately 15 mA is needed for a wide range of applications capable of accommodating commerciallyavailable film, suitable for the sample sizes to be X-rayed, and suitable
34、for the sample holders. The equipment may be equippedwith a fluoroscope.with a voltage outout of 100 kV is often used, certain types of samples may require equipment capable of2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For
35、 Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.D4452 142performing at lower voltages (for example, 40 kV). For maximum resolution in certain types of applications a fine focus X-raytube may be necessary. Persons inexperienced with X
36、-ray radiography should discuss their specific equipment needs and therequirements of these methods with equipment manufacturers prior to purchasing.NOTE 2Certain types of samples may require equipment capable of performing at lower voltages (for example, 40 kV). In such instances, equipmentwith low
37、er voltages can be substituted for that required in 5.1. For maximum resolution in certain types of applications a fine-focus X-ray tube may benecessary. Persons inexperienced with X-ray radiography should discuss their specific equipment needs and the requirements of these methods withequipment man
38、ufacturers prior to purchasing.NOTE 3Equipment with berryllium window X-ray tubes may be necessary to perform radiography at low voltages.NOTE 2Equipment with beryllium window X-ray tubes may be necessary to perform radiography at low voltages.5.3 Solid Slice Trough, Trough as An example trough is s
39、hown in Fig. 1 or, other suitable trough. .5.4 Extruded Tube Sample Holder , Holder, as An example of this type of holder is shown in Fig. 2, or other suitable holders.5.5 Thin Wall Tube Holders, as An example of this type of holder is shown in Fig. 3, or other suitable holders5.6 Measuring Tape, mi
40、nimum 36 in. (914 mm)900 mm (36 in.) long.5.7 Personal Dosimeters or Film Badges.5.8 Small Hand Tools, such as wire saws, spatulas, and knives.h = d = d 13 mm (12 in. (12.7 mm)in.)d = diameter of the sample to be slicedL = varies to suit sample lengthFIG. 1 Example of Soil Slice Trough and HolderL =
41、 variable length to suit the length of the sampled = inside diameter of sampling tube usedW = d + 2 in. (51 mm) = d + 50 mm (2 in.)H = d + 0.25 in. (6.4 mm) = d + 6.5 mm (0.25 in.)FIG. 2 Example of Extruded Tube Sample HolderD4452 1435.9 Industrial Type X-Ray Film , Film, or equivalent.5.10 Intensif
42、ying Screens, made of sheets of thin lead.5.11 Alphanumeric Lead Markers . Markers.6. Safety Precautions6.1 Radiation safety and policies for the use of X-ray radiography machines applicable to these methods should be establishedbased on federal,national, state, and institutional requirements meetin
43、g acceptable radiation safety standards, such as thoseestablished by the National Council on Radiation Protection and Measurements (NCRP).standards.7. Procedures7.1 Tubes and LinersTubes and Liners:7.1.1 Place the thin wall tube or liner holding the soil sample in the appropriate size sample holder,
44、 such as the one shown inFig. 3. If such a holder is not available, pack the tube sample in sand, clay, or plaster of paris,Paris, forming an approximatelyrectangular cross-section, as shown in Fig. 3.7.1.2 Load suitable X-ray film. Place the Set up the equipment for imaging. If using film, an inten
45、sifying lead screen may beplaced in contact with the film.7.1.3 Position the sample and adjust the equipment so that the distance from the X-ray source to the film or detector plateprovides the best possible radiograph. Experience has shown that a distance of not less than 30 in. (762 mm)760 mm (30
46、in.) isappropriate for most samples. Place the alphanumeric lead identification markers next to, or on, the portion of the sample that wasclosest to the ground surface in situ that will be included in the X ray. If more than one exposure is required to cover the entirelength of the sample, a lead ma
47、rker should be placed to serve as a match mark.7.1.4 Adjust the output to a level which will provide the clearest radiograph or fluoroscopic image of the sample. The outputis to be determined by the user.7.1.5 Expose the film or detector plate an appropriate length of time. Process the exposed film
48、following film developingmethods results as recommended by the manufacturer. The exposure time may vary with equipment, type of soil, or type of tubingmaterial used. It is advisable to experiment with the exposure time, keeping the distance of the specimen from film or detector plateconstant until w
49、ell-defined, clear, X-ray radiographs are obtained. Adjustments also can be made by keeping the exposure timeconstant and by varying the distance of the X-ray source from the film.film or detector plate.7.1.6 Rotate the sample 90 about its longitudinal axis and repeat the procedure. Identify the 0 and 90 exposures with leadmarkers.7.1.7 For some applications it may be sufficient to prepare samples as in 7.1.1 7.1.3 and simply observe various features onthe fluoroscope; in such cases, eliminate 7.1.47.1.5.7.2 Extruded SamplesExtruded Samples:7.2.1 Specimen
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