1.1 本试验方法描述了在锤击土壤的动态贯入仪试验期间，测量进入贯入仪钻杆柱的能量的程序。 1.2 本试验特别适用于从裸眼土壤标准贯入试验（SPT）中获得的N值的比较评估，如试验方法所示 D1586 和实践 D6066 . 该程序也适用于其他动态贯入仪试验。 1.3 以国际单位制表示的数值应视为标准值。括号中给出的英寸-磅单位是数学转换，仅供参考，不被视为标准。 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。 1.3.1 转换后的英寸-磅单位使用重力单位制。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，否则未给出转换后的段塞单元。 1.4 限制- 本试验方法适用于从地面上方驱动的贯入仪。它不适用于井下锤。 1.5 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 . 1.5.1 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。 1.6 本标准的文本引用了提供解释材料的注释和脚注。这些注释和脚注（不包括表和图中的注释和脚注）不应视为本标准的要求。 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和健康实践，并确定监管限制的适用性。 ====意义和用途====== 4.1 使用各种驱动的现场贯入仪来评估土壤的工程行为。 标准贯入试验是最常见的类型。可以根据N值与土壤密度、强度或刚度之间的经验相关性来估计工程特性。或者，可以使用与设计参数（如容许承载力或桩承载力）的相关性，在基础设计中直接使用N值。N值取决于土壤性质，但也取决于质量、几何形状、冲程、铁砧和锤子的工作效率。该能量测量程序可以评估由液压锤系统中的差异引起的N值变化。 另见参考文献 ( 1- 6. ) . 3. 4.2 贯入仪的增量贯入度与进入钻杆的锤子能量之间存在近似的线性关系，因此N值与传递给钻杆的能量之间存在近似的反比关系。 注1: 由于测得的能量包括因每次锤击设定而产生的额外势能效应，因此锤击系统的能量评估试验应限制在10到50之间的中等N值范围内（参考 ( 7. ) ). 4.3 贯入仪上的应力波能量测量可以评估两种操作员- 独立猫头和绳锤系统以及相对独立于操作员的自动系统。 4.4 实践证明，能量测量可直接用于砂土液化评价 D6066 . 4.5 该试验方法有助于比较在同一场地进行SPT试验的不同设备或操作员产生的N值，有助于贯入仪系统的设计，培训动态贯入仪系统操作员，并开发不同类型动态贯入试验之间的转换系数。 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的测试/采样/检查等。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:实践 D3740 提供了一种评估其中一些因素的方法。

1.1 This test method describes procedures for measuring the energy that enters the penetrometer drill rod string during dynamic penetrometer testing of soil due to the hammer impact. 1.2 This test has particular application to the comparative evaluation of N-values obtained from the Standard Penetration Tests (SPT) of soils in an open hole as in Test Method D1586 and Practice D6066 . This procedure may also be applicable to other dynamic penetrometer tests. 1.3 The values stated in SI units are to be regarded as standard. The inch-pound units given in parentheses are mathematical conversions which are provided for information purposes only and are not considered standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method. 1.3.1 The converted inch-pound units use the gravitational system of units. In this system, the pound (lbf) represents a unit of force (weight), while the unit for mass is slugs. The converted slug unit is not given, unless dynamic (F = ma) calculations are involved. 1.4 Limitations— This test method applies to penetrometers driven from above the ground surface. It is not intended for use with down-hole hammers. 1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 . 1.5.1 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 of 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. 1.6 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard. 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 and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== 4.1 Various driven in situ penetrometers are used to evaluate the engineering behavior of soils. The Standard Penetration Test is the most common type. Engineering properties can be estimated on the basis of empirical correlations between N-values and soil density, strength or stiffness. Alternatively, the N-value can be used directly in foundation design using correlations to design parameters such as allowable bearing pressure or pile capacity. The N-value depends on the soil properties but also on the mass, geometry, stroke, anvil, and operating efficiency of the hammer. This energy measurement procedure can evaluate variations of N-value resulting from differences in the hammer system. See also Refs ( 1- 6 ) . 3 4.2 There is an approximate, linear relationship between the incremental penetration of a penetrometer and the energy from the hammer that enters the drill rods, and therefore an approximate inverse relationship between the N-value and the energy delivered to the drill rods. Note 1: Since the measured energy includes the extra potential energy effect due to the set per blow, tests for energy evaluation of the hammer systems should be limited to moderate N-value ranges between 10 and 50 (Ref ( 7 ) ). 4.3 Stress wave energy measurements on penetrometers may evaluate both operator-dependent cathead and rope hammer systems and relatively operator-independent automatic systems. 4.4 The energy measurement has direct application for liquefaction evaluation for sands as referenced in Practice D6066 . 4.5 This test method is useful for comparing the N-values produced by different equipment or operators performing SPT testing at the same site, aiding the design of penetrometer systems, training of dynamic penetrometer system operators, and developing conversion factors between different types of dynamic penetration tests. 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/sampling/inspection/etc. Users of this standard 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.