1.1 这些规程规定了从现场获得的钻芯或用于强度和变形测试的块体样品中制备岩芯岩石试样的程序，以及确定试样尺寸与本规程确定的公差的一致性的程序。本规程不包括立方体、矩形或其他形状。然而，本规程和标准试验方法中包含的一些信息 C170 可能仍用于制备其他试样形状。 1.2 岩石是一种复杂的工程材料，随着岩性、应力历史、风化、含水量和化学以及其他自然地质过程的变化而变化很大。因此，并非总是能够获得或制备满足本规程中给出的理想公差的岩芯样本。最常见的情况是，这种情况表现为较弱、更多孔和胶结不良的岩石类型，以及包含显著或较弱（或两者）结构特征的岩石类型。 对于难以制备的岩石类型，应尽一切合理努力根据本规程和预期试验程序制备试样。然而，当通过反复试验确定这是不可能的时，将岩石样本制备到最接近的公差，并认为这是最大的努力( 注1 )并如实报告，如果预期试验允许或必要，则允许按照本规程中的讨论对试样端部进行封盖。 注1: 尽最大努力进行表面处理是指使用维护良好、合适的平面磨床、车床或研磨机，以及由经验丰富的操作员使用的任何所需辅助设备，并在其中进行了合理的尝试，以满足本程序中要求的公差。 1.3 这种做法涵盖了一些但不是所有应该实施的策展问题。 关于标本制备之前和期间应遵循的管理问题，请参阅实践 D5079 并符合中的具体测试标准 2.1 正在为其制备样本。 1.4 本规程还规定了长径比、圆柱面上元件的平直度、端承表面的平整度以及端面与芯轴的垂直度的公差检查。 注2: 本规程并未涵盖可能会或可能会遇到的所有问题，这些问题可能会控制所需样本制备的质量。每个实验室可能都有自己的问题，尤其是对于不同的压缩载荷框架或岩石类型。例如，刚性测试框架与传统负载框架和负载板（带或不带球形底座）相比。根据被测岩石的类型，无球形底座的刚性测试荷载框架的试样可能需要有更严格的要求。 本程序试图展示可能涉及的方法和QA，同时牢记那些难以使用且样本仍适合测试的材料。本标准尽可能考虑D18.12成员关于该主题的可用文献和输入。 2. 1.5 还说明了规定试样湿度条件和体积的要求。但是，具体测试标准中的要求 2.1 也应该遵循。 1.6 所有观察值和计算值应符合实践中确定的有效数字和舍入准则 D6026 ，除非被本标准取代。 1.6.1 本标准中用于规定如何收集/记录和计算数据的实践/程序被视为行业标准。此外，它们代表了通常应保留的有效数字。 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因素；通常的做法是增加或减少报告数据的有效位数，以与这些考虑因素相称。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。 1.7 单位- 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。如适用，添加“以英寸磅以外的单位报告试验结果不应视为不符合本标准。” 1.7.1 缓动质量单位通常不用于商业实践；即密度、平衡等。因此，本标准中质量的标准单位为千克（kg）或克（g）或两者兼有。 此外，括号中未给出/显示等效英寸-磅单位（slug）。 1.7.2 工程/建筑行业的常见做法是同时使用磅来表示质量单位（lbm）和力（lbf）。这种做法隐含地结合了两个独立的单位制；绝对系统和引力系统。在一个标准中结合使用两套独立的英寸-磅单位在科学上是不可取的。如前所述，本标准包括英寸-磅单位的重力系统，不使用/呈现质量的段塞单位。然而，使用天平或天平记录磅质量（lbm）或记录密度（lbm/ft） 3. 不应视为不符合本标准。 1.8 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.9 这些实践为执行一个或多个特定操作提供了一组说明。本文件不能取代教育或经验，应与专业判断结合使用。并非本惯例的所有方面都适用于所有情况。本ASTM标准不代表或取代必须根据其判断给定专业服务的充分性的谨慎标准，也不应在不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。 1.10 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====== 4.1 岩芯试样的尺寸、形状和表面公差对于确定完整试样的岩石特性非常重要。对于大于7250 psi（50 MPa）的坚硬岩石和将在没有球形底座的刚性测试荷载框架中进行测试的岩石样本，这一点尤其正确，因为可能会发生非均匀荷载。第节中列出的试验方法中要求进行尺寸和表面公差检查 2.1 . 为了简化实验室中的测试程序，这些程序中与第节中的测试方法通用的部分 2.1 在本标准中给出。 4.2 本程序适用于第节中列出的所有标准 2.1 ; 然而，试验方法的样本 D2936 无需进行机械加工或满足规定的平面度和平行度公差。 4.3 样品制备时样品的水分条件会对岩石的强度和变形特性产生重大影响。 良好实践通常要求在代表现场条件的样本上进行实验室测试。因此，应将试样的现场水分条件保存到试验时。然而，在某些情况下，可能有理由在其他含水量（从饱和到干燥）下测试样本。在任何情况下，应根据手头的问题调整试样的含水量。 注3: 关于含水量的讨论在许多岩石测试标准中很常见，但处理和报告该问题都需要专业判断。例如，在获取样品或制备样品时，可能需要或使用水或某些其他冷却剂。因此，一个或多个样本中的水分可能与原位不同；这适用于水化学和流体量。应解决这个问题，并为从采样到测试阶段的每个步骤制定一个计划，以记录/报告为成功制备可测试样品建议的步骤。 通常需要在保存原位条件、成本、实验室控制范围外的条件和获得可测试样本之间进行折衷。例如，导致样品或试样破裂的水分损失可能比原位水测试或原位含水量测试或两者都测试更令人担忧。 4.4 过多的水分会影响电阻应变计（如果使用）的附着力及其性能的准确性。在直接拉伸试验中，用于将岩石与钢端盖和固定装置粘结在一起的粘合剂，用于将试样连接到负载架的致动器和十字头上( D2936 )也会受到过多水分的不利影响。 注4: 这些实践产生的结果的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 D3740 通常认为能够胜任客观的测试和采样。 提醒这些实践的用户遵守实践 D3740 本身并不能保证可靠的结果。可靠的结果取决于许多因素；实践 D3740 提供了一种评估其中一些因素的方法。

1.1 These practices specify procedures for preparing rock test specimen of rock core from drill core obtained in the field or from block samples for strength and deformation testing and for determining the conformance of the test specimen dimensions with tolerances established by this practice. Cubical, rectangular, or other shapes are not covered by this practice. However, some of the information contained within this practice and in standard Test Method C170 may still be of use to preparing other test specimen shapes. 1.2 Rock is a complex engineering material that can vary greatly as a function of lithology, stress history, weathering, moisture content and chemistry, and other natural geologic processes. As such, it is not always possible to obtain or prepare rock core specimens that satisfy the desirable tolerances given in this practice. Most commonly, this situation presents itself with weaker, more porous, and poorly cemented rock types and rock types containing significant or weak (or both) structural features. For rock types which are difficult to prepare, all reasonable efforts should be made to prepare a specimen in accordance with this practice and for the intended test procedure. However, when it has been determined by trial and error that this is not possible, prepare the rock specimen to the closest tolerances practicable and consider this to be the best effort ( Note 1 ) and report it as such and if allowable or necessary for the intended test, capping the ends of the specimen as discussed in this practice is permitted. Note 1: Best effort in surface preparation refers to the use of a well-maintained, suitable surface grinder, lathe or lapping machine and any required ancillary equipment are utilized by an experienced operator and in which a reasonable number of attempts has been made to meet the tolerances required in this procedure. 1.3 This practices covers some, but not all of the curatorial issues that should be implemented. For curatorial issues that should be followed before and during specimen preparation refer to Practices D5079 and to the specific test standards in 2.1 for which the specimens are being prepared. 1.4 This practice also prescribes tolerance checks on the length-to-diameter ratio, straightness of the elements on the cylindrical surface, the flatness of the end bearing surfaces, and the perpendicularity of the end surfaces with the axis of the core. Note 2: This practice does not purport to cover all the issues that will or could be encountered that may control the quality of the specimen preparation required. Each laboratory may have their own issues, especially for different compression load frames or rock types. For example, stiff testing frames versus traditional load frames and loading platens with or without spherical seating. Specimens for a stiff testing load frame with no spherical seat may need to have more stringent requirements depending on the type of rock being tested. This procedure has tried to show the methods and QA that may be involved while keeping in mind those materials that are difficult to work with and for which the specimens will still be suitable to be tested. The available literature and input on this subject from D18.12 members were considered as much as possible for this standard. 2 1.5 The requirement for specifying the moisture condition and volume of the test specimen is also stated. However, the requirements in the specific test standards in 2.1 should be followed too. 1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 , unless superseded by this standard. 1.6.1 The practices/procedures used to specify how data are collected/recorded and calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant 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. 1.7 Units— The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. Add if appropriate, “Reporting of test results in units other than inch-pound shall not be regarded as nonconformance with this standard.” 1.7.1 The slug unit of mass is typically not used in commercial practice; that is, density, balances, and so on. Therefore, the standard unit for mass in this standard is either kilogram (kg) or gram (g) or both. Also, the equivalent inch-pound unit (slug) is not given/presented in parentheses. 1.7.2 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and of force (lbf). This practice implicitly combines two separate systems of units; the absolute and the gravitational systems. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. As stated, this standard includes the gravitational system of inch-pound units and does not use/present the slug unit for mass. However, the use of balances or scales recording pounds of mass (lbm) or recording density in lbm/ft 3 shall not be regarded as nonconformance with this standard. 1.8 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. 1.9 These practices offer 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 judgement. 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. 1.10 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 ====== 4.1 The dimensional, shape, and surface tolerances of rock core test specimens are important for determining rock properties of intact specimens. This is especially true for strong rocks, greater than 7250 psi (50 MPa) and for rock specimens that will be tested in stiff testing load frames without a spherical seat where non-uniform loading could occur. Dimensional and surface tolerance checks are required in the test methods listed in Section 2.1 . To simplify test procedures in laboratories, the parts of those procedures that are common to the test methods in Section 2.1 are given in this standard. 4.2 This procedure is applicable to all the standards listed in Section 2.1 ; however, specimens for Test Method D2936 do not need to be machined or to meet the specified tolerances for flatness and parallelism. 4.3 The moisture condition of the specimen at the time of the sample preparation can have a significant effect upon the strength and deformation characteristics of the rock. Good practice generally dictates that laboratory tests be made upon a specimens’ representative of field conditions. Thus, it follows that the field moisture condition of the specimen should be preserved until the time of the test. In some instances, however, there may be reasons for testing specimens at other moisture contents, from saturation to dry. In any case, the moisture content of the test specimen should be tailored to the problem at hand. Note 3: Discussions on moisture content are common in many rock testing standards but professional judgement will be needed to both handle and report this issue. For example, when obtaining the samples or preparing the specimens, water or some other cooling agent may be required or used. Therefore, the moisture in the specimen or samples may not be what it was in situ; this applies to both water chemistry and quantity of fluids. This issue should be addressed, and a plan put in place for each step from the sampling to the testing phase in a manner that records/reports what steps were advised to successfully prepare testable samples. Usually a compromise between preserving in-situ conditions, costs, conditions outside the control of the laboratory and obtaining testable specimens is required. For example, loss of moisture that leads to the samples or specimens falling apart may be of greater concern than testing with in situ water or at the in situ water content or both. 4.4 Excess moisture will affect the adhesion of resistance strain gages, if used, and the accuracy of their performance. Adhesives used to bond the rock to steel end caps and fixtures for attaching specimens to actuators and crosshead of the load frame in the direct tension test ( D2936 ) will also be affected adversely by excess moisture. Note 4: The quality of the result produced by these practices is dependent upon 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 and sampling. Users of these practices are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.