1.1 本规程涵盖了用X射线照相法测定薄壁管中土壤样品或挤压土壤芯的质量。 1.2 这种做法使用户能够通过X射线穿过土壤样品的相对穿透程度来确定采样和样品内自然变化的影响。 1.3 这种做法可用于直径约为50至150 mm[2至6 in.]的薄壁管或内衬中的X射线土壤芯（或在荧光镜上观察其特征）。大直径管中样品的X射线照片提供了土壤和扰动的主要特征的射线照片，例如弯曲粘土边缘的大规模弯曲、剪切面、存在较大的结核、淤泥和厚度大于6mm的砂层[ 1. / 4. 英寸]，大的有机物质块和空隙或其他类型的侵入体。较小直径岩芯的X射线可提供更高分辨率的土壤特征和扰动，例如小的结核（3 mm[ 1. / 8. 英寸]直径或更大）、溶解通道、弯曲粘土边缘的轻微弯曲、薄粉土或砂层、狭窄的溶解通道、植物根系结构和有机物。对薄壁管或内衬中的样品进行X射线检查需要最少的准备。 1.4 与金属管中的样品相比，通过X射线对挤压的土壤芯进行扫描，可以获得更详细的土壤特征和分辨率。用于X射线土壤芯的方法与用于管和衬里的方法相同，除了挤压芯必须极其小心地处理，并且必须放置在样品槽中（类似于图。 2） 在X射线之前。仅当天然含水量或其他完整土壤特性与样品的最终用途无关时，才应使用此做法。 1.4.1 通常需要获得更高的特征分辨率，以确定取样方法的适当性、土壤样品的代表性或土壤中的异常。这种做法要求获得重复样品或对已经测试的样品进行X射线检查。 1.5 只有在通过X射线图像和X射线样本之间的许多详细比较获得大量经验之后，才能充分利用这种做法。 1.6 单位- 以国际单位制或英磅制单位表示的数值[在括号内]应单独视为标准值。 每个系统中规定的值可能不完全相等；因此，每个系统应独立使用。将两个系统的值结合起来可能会导致不符合标准。 1.7 本实践提供了一组用于执行一个或多个特定操作的说明。本文件不能取代教育或经验，应与专业判断一起使用。并非本惯例的所有方面都适用于所有情况。本ASTM标准并非旨在代表或取代判断特定专业服务是否充分的谨慎标准，也不应在未考虑项目的许多独特方面的情况下应用本文件。本文件标题中的“标准”一词仅表示该文件已通过ASTM共识程序获得批准。 1.8 所有观察值和计算值应符合实践中制定的有效数字和四舍五入指南 第6026页 . 1.8.1 为了将测量或计算值与规定限值进行比较，应将测量值或计算值四舍五入到规定限值中最接近的小数或有效数字。 1.8.2 本标准中用于规定数据收集/记录或计算方式的程序被视为行业标准。此外，它们代表了通常应保留的含义数字。使用的程序不考虑材料变化、获取数据的目的、特殊目的研究或用户目标的任何考虑；通常的做法是增加或减少报告数据的有效位数，以与这些考虑相称。 考虑工程设计分析方法中使用的有效数字超出了本标准的范围。 1.9 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 有关具体的预防说明，请参见第节 7. . 1.10 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 许多岩土工程试验要求使用完整的、具有代表性的土壤样品。这些样品的质量取决于许多因素。通过完整取样方法获得的许多样品具有固有的异常。采样程序会引起不同类型和强度的干扰。然而，这些异常和干扰并不总是通过在测试前后对完整样品进行目视检查而容易检测到。通常，如果在测试之前或在通过测试破坏样品之前知道这些异常和干扰的存在和程度，测试结果会得到提高。此类测定有助于用户检测取样方法中的缺陷、天然或诱发剪切面的存在、以及天然侵入体的存在，如样品关键区域的砾石或贝壳、砂层和粉砂层的存在以及取样引起的扰动强度。 5.2 X射线照相术为用户提供了土壤样品内部块状结构的图片，而不管土壤是否在取样管内进行X射线照相。X射线照相术帮助用户识别以下内容: 5.2.1 所用取样方法的适当性。 5.2.2 取样的影响，包括弯曲土壤中各薄层边缘的旋转引起的扰动、软土中的大扰动、取样或挤压引起的剪切面，或二者兼而有之、采样器过度驱动的影响、取样管中存在岩屑，或使用弯曲、腐蚀或非标准管进行取样的影响。 5.2.3 天然裂缝、剪切面等。 5.2.4 样品中存在侵入体，如钙质结核、砾石或贝壳。 5.2.5 砂层和淤泥层、有机质、大孔隙以及通过自然或人工淋滤土壤成分而形成的沟渠。 注1: 本标准产生的结果质量取决于执行人员的能力以及所用设备和设施的适用性。符合实践标准的机构 第3740列 通常被认为能够胜任和客观的测试/取样/检查等。本标准的使用者应注意遵守实践 第3740列 其本身不能确保可靠的测试。可靠的测试取决于许多因素；实践 第3740列 提供了评估其中一些因素的方法。

1.1 This practice covers the determination of the quality of soil samples in thin wall tubes or of extruded soil cores by X-ray radiography. 1.2 This practice enables the user to determine the effects of sampling and natural variations within samples as identified by the extent of the relative penetration of X-rays through soil samples. 1.3 This practice can be used to X-ray soil cores (or observe their features on a fluoroscope) in thin wall tubes or liners ranging from approximately 50 to 150 mm [2 to 6 in.] in diameter. X-rays of samples in the larger diameter tubes provide 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 concretions, silt and sand seams thicker than 6 mm [ 1 / 4 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 and disturbances, such as small concretions (3 mm [ 1 / 8 in.] diameter or larger), solution channels, slight bending of edges of varved clays, thin silt or sand seams, narrow solution channels, plant root structures, and organic matter. The X-raying of samples in thin wall tubes or liners requires minimal preparation. 1.4 Greater detail and resolution of various features of the soil can be obtained by X-raying extruded soil cores, as compared to samples in metal tubes. The method used for X-raying soil cores is the same as that for tubes and liners, except that extruded cores have to be handled with extreme care and have to be placed in sample troughs (similar to Fig. 2) before X-raying. This practice should be used only when natural water content or other intact soil characteristics are irrelevant to the end use of the sample. 1.4.1 Often it is necessary to obtain greater resolution of features to determine the propriety of sampling methods, the representative nature of soil samples, or anomalies in soils. This practice requires that either duplicate samples be obtained or already tested specimens be X-rayed. 1.5 This practice can only be used to its fullest extent after considerable experience is obtained through many detailed comparisons between the X-ray image and the sample X-rayed. 1.6 Units— The values stated in either SI units or inch-pound units [presented in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with standard. 1.7 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project’s many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process. 1.8 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 . 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. 1.8.2 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industry standard. In addition, they are representative of the signification digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of 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 responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precaution statements, see Section 7 . 1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Many geotechnical tests require the utilization of intact, representative samples of soil. The quality of these samples depends on many factors. Many of the samples obtained by intact sampling methods have inherent anomalies. Sampling procedures cause disturbances of varying types and intensities. These anomalies and disturbances, however, are not always readily detectable by visual inspection of the intact samples before or after testing. Often test results would be enhanced if the presence and the extent of these anomalies and disturbances are known before testing or before destruction of the sample by testing. Such determinations assist the user in detecting flaws in sampling methods, the presence of natural or induced shear planes, and the presence 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 disturbances caused by sampling. 5.2 X-ray radiography provides the user with a picture of the internal massive structure of the soil sample, regardless of whether the soil is X-rayed within or without the sampling tube. X-ray radiography assists the user in identifying the following: 5.2.1 Appropriateness of sampling methods used. 5.2.2 Effects of sampling in terms of the disturbances caused by the turning of the edges of various 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. 5.2.3 Naturally occurring fissures, shear planes, etc. 5.2.4 The presence of intrusions within the sample, such as calcareous nodules, gravel, or shells. 5.2.5 Sand and silt seams, organic matter, large voids, and channels developed by natural or artificial leaching of soil components. Note 1: The quality of the results produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself ensure reliable testing. Reliable testing depends on many factors; Practice D3740 provides a means of evaluating some of those factors.