1.1 本试验方法包括在饱和粘土和粉土中进行现场十字板试验，以测定不排水抗剪强度。要评估试验的适用性和解释，需要了解进行每个十字板试验的土壤性质。本试验不适用于砂土或非塑性粉土，这可能会在试验期间允许排水。 1.2 本试验方法涉及陆上试验和钻孔试验，或通过自钻或连续推土方法从地面进行试验。该方法不专门针对可能需要特殊测试要求或设备变化的海洋测试。用户可参考ASTM STP 1014，了解海洋勘探中使用的现场十字板剪切试验的更多信息。 2. 1.3 该方法通常与流体旋转钻井结合使用( D5783 )、空心杆螺旋钻( D6151/D6151M )，或锥贯入试验( D5778 ). 一些设备将叶片缩回保护靴中，用于推进和增量测试。取样，例如使用薄壁管( D1587/D1587M )通常与叶片测试相结合。根据实践报告地下岩土勘探( D5434 ). 1.4 粘性土的不排水抗剪强度和敏感性也可以在实验室十字板试验中测量( D4648/D4648M ). 1.5 单位- 以国际单位制或英寸-磅单位表示的数值[括号内]应单独视为标准值。每个系统中的值可能不是精确等价的；因此，每个系统应相互独立使用。将两个系统的值合并可能会导致不符合标准。 以国际单位制以外的单位报告试验结果不应视为不符合本试验方法。 1.5.1 在处理英寸磅单位时，使用英寸磅单位的重力系统。在这个系统中，磅（lbf）表示力（重量）的单位，而质量的单位是段塞。除非涉及动态（F=ma）计算，否则未给出合理化的段塞单元。 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 . 1.6.1 本标准中用于规定如何收集/记录或计算数据的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，通常做法是增加或减少有效数字或报告数据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 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。 1.8 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 本试验方法提供了以下方面的指示:- 饱和细粒土（粘土和粉土）或其他饱和细粒土材料（如尾矿和有机淤泥）的原位不排水抗剪强度。该试验适用于不排水强度小于200 kPa[2 tsf]的土壤。非常敏感的土壤可以在插入叶片期间重塑。 5.2 该试验方法广泛用于各种岩土工程勘察，以评估饱和细粒粘土和粉土总应力分析的快速加载强度。由于叶片剪切强度值通常高于分析的场强( 5.3 )通常会对其进行检查或与其他测量不排水剪切强度的方法进行比较。圆锥贯入仪试验（试验方法 D5778 )和未固结不排水三轴压缩( D2850 )试验通常用于与叶片抗剪强度数据进行直接比较。 无侧限压缩( D2166/D2166M )也可以进行测试，但由于干扰，尤其是在裂隙粘土中，可能会出现许多错误，因此只能根据经验进行测试。有关如何将这些测试用于软土场地勘探的更多信息，请参阅Ladd和DEGROT。 ( 1. ) 4. 5.3 通常对十字板试验的峰值不排水剪切阻力进行校正，以确定岩土分析的不排水剪切强度。要求测试的机构必须解释这些数据，以确定强度分析的适用性。为岩土分析推荐十字板试验的适用性超出了本标准的范围。有关这些校正因子的一般使用信息，请参阅 附录X1 . 5.4 该方法不适用于非饱和土或非饱和土- 塑性粉土、砂、砾石或其他高渗透性土壤。根据本标准中所述的剪切速率，砂透镜体（如果存在）将允许全部或部分排水。非饱和土和渗透性较高的土壤在快速剪切时会膨胀或坍塌，并产生负或正孔隙压力，这些压力可能在剪切过程中消散，也可能不会消散。检查正在测试的土壤类型很重要。在测试之前或之后对土壤进行采样，以了解测试土壤的排水条件（渗透性），这是非常有益的。 5.5 该方法也适用于在较浅深度进行的手持式叶片剪切试验，然而，手持式设备可能不太准确，因为它可能更难保持叶片/杆的稳定性和垂直度。 注2: 本标准产生的结果的质量取决于执行该标准的人员的能力，以及所用设备和设施的适用性。 符合实践标准的机构 D3740 通常认为能够胜任和客观测试。本标准的用户应注意遵守惯例 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；标准实践 D3740 提供了一种评估其中一些因素的方法。

1.1 This test method covers the field vane test in saturated clay and silt soils for determination of undrained shear strength. Knowledge of the nature of the soil in which each vane test is to be made is necessary for assessment of the applicability and interpretation of the test. The test is not applicable for sandy soils or non-plastic silts, which may allow drainage during the test. 1.2 This test method addresses testing on land and for testing in drill holes or by self-drilling or continuous push methods from the ground surface. This method does not address specifically marine testing where special test requirements or variations in equipment may be required. The user is referred to ASTM STP 1014 for additional information on in-place vane shear testing used in marine exploration. 2 1.3 This method is often used in conjunction with fluid rotary drilling ( D5783 ), hollow-stem augers ( D6151/D6151M ), or cone penetration testing ( D5778 ). Some apparatuses have the vane retracted in a protective shoe for advancement and incremental testing. Sampling, such as with thin wall tubes ( D1587/D1587M ) is often combined with vane testing. Subsurface geotechnical explorations are reported in accordance with Practice ( D5434 ). 1.4 Undrained shear strength and sensitivity of cohesive soils can also be measured in Laboratory Vane Test ( D4648/D4648M ). 1.5 Units— The values stated in either SI units or inch-pound units [presented in brackets] are to be regarded separately as standard. The values 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 non-conformance with the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method. 1.5.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf) represents a unit of force (weight), while the unit for mass is slugs. The rationalized slug unit is not given, unless dynamic (F = ma) calculations are involved. 1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 . 1.6.1 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 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 or reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analytical methods for engineering design. 1.7 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. 1.8 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 This test method provides an indication of in-situ undrained shear strength of saturated fine-grained soils (clays and silts) or other saturated fine-grained geomaterials, such as mine tailings and organic muck. The test is applicable to soils with undrained strengths of less than 200 kPa [2 tsf]. Very sensitive soils can be remolded during vane insertion. 5.2 This test method is used extensively in a variety of geotechnical explorations to evaluate rapid loading strength for total stress analysis of saturated fine-grained clays and silts. Since vane shear strength values are most always higher than field strengths for analyses ( 5.3 ) they often are checked or compared with other methods of measuring undrained shear strength. Cone Penetrometer Tests (Test Method D5778 ) and Unconsolidated Undrained Triaxial Compression ( D2850 ) tests are most often performed for direct comparison to the vane shear strength data. Unconfined Compression ( D2166/D2166M ) testing could also be performed, but suffers from many possible errors from disturbance especially in fissured clays, and should only be performed with experience. For more information on how these tests are used for soft ground site exploration refer to Ladd and DeGroot. ( 1 ) 4 5.3 The peak undrained shear resistance of the vane test is commonly corrected to determine the undrained shear strength for geotechnical analysis. The agency requesting the testing must interpret these data to determine applicability for strength analysis. It is beyond the scope of this standard to recommend applicability of vane testing for geotechnical analysis. For information on the general use of these correction factors, consult Appendix X1 . 5.4 This method is not applicable in unsaturated soils or in non-plastic silts, sands, gravels, or other high permeability soils. With the shearing rates described in this standard, sand lenses, if present, will allow total or partial drainage. Unsaturated soils and soils with higher permeability, in rapid shear, can dilate or collapse and generate negative or positive pore pressures which may, or may not, dissipate in the shearing process. It is important to check the soil type being tested. It is very beneficial to sample the soil either before or after testing, to understand the drainage conditions (permeability) of the soil tested. 5.5 This method also applies to hand held vane shear tests performed at shallow depths, however, hand held equipment may be less accurate, because it may be more difficult to maintain vane/rod stability and verticality. Note 2: The quality of the result 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. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Standard Practice D3740 provides a means of evaluating some of those factors.