1.1 该动态测试方法涵盖了使用打桩锤或大落锤施加轴向冲击力的程序，该冲击力将在单个垂直或倾斜深基础单元的顶部产生相对较高的应变，并测量该深基础单元的后续力和速度响应。虽然在本标准中，力和速度被称为“测量”，但它们通常来自测量的应变和加速度值。高应变动态测试适用于任何深基础单元，此处也称为“桩”，其功能类似于打入桩或灌注桩，无论安装方法如何，并且符合本测试方法的要求。 1.2 本标准规定了深基础动态测试的最低要求。合格工程师编制的计划、规范或规定（或其组合）可提供满足特定测试计划目标所需的额外要求和程序。 负责基础设计的工程师（以下简称“工程师”）应批准对本标准要求的任何偏差、删除或添加。 1.3 正确进行和评估高应变动态测试需要特殊的知识和经验。合格的工程师应直接监督现场数据的采集和测试结果的解释，以预测建造基础中使用的深基础的实际性能和充分性。合格工程师应批准用于施加冲击力的装置、驱动附件、测试索具、提升设备、支架、模板和测试程序。 1.4 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。 “应”一词表示强制性规定，“应”一词表示建议或咨询性规定。祈使句表示强制性规定。 1.5 单位- 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。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。 1.6 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/记录和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。 1.7 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。 有关具体的预防说明，请参阅 附注4 . 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====== 4.1 该测试方法获得了轴向冲击事件期间桩中感应的力和速度（见 无花果。1和 2. ). 力和速度通常来自测量的应变和加速度。工程师可以使用工程原理和判断分析获得的数据，以评估桩的完整性、冲击系统的性能以及桩中出现的最大压应力和拉应力。 图2 深基础高应变动态测试的典型布置 4.2 如果在冲击事件期间发生足够的轴向移动，并且在评估沿桩侧和桩底产生的动态土壤响应后，工程师可以分析高应变动态测试的结果，以估计极限轴向静态压缩能力（见 注1 ). 可能影响动态试验估算的轴向静态承载力的因素包括但不限于: (1) 桩安装设备和程序， (2) 自初始安装以来经过的时间， (3) 桩材料特性和尺寸， (4) 桩附近和下方土壤或岩石的类型、密度、强度、分层和饱和度， (5) 动态测试数据的质量或类型， (6) 基础沉降， (7) 分析方法，以及 (8) 工程判断和经验。 如果工程师在这些因素和动态测试数据分析方面没有足够的经验，则根据测试方法进行静态负载测试 D1143/D1143M 应用于验证静态承载力的估计及其沿桩长的分布。试验方法 D1143/D1143M 提供静态容量的直接和更可靠的测量。 注1: 如果冲击事件期间的桩移动过小，则动态测试分析将低估极限轴向静态压缩能力。 工程师应确定桩的尺寸和形状，以及桩下方和附近土壤或岩石的性质如何影响充分调动静态承载力所需的移动量。每次撞击的永久净贯入度小于2 mm可能表明撞击事件期间发生了足够的移动，以充分调动承载力。然而，高位移打入桩可能需要更大的移动，以避免低估静态承载力，而灌注桩通常需要更大的累积永久净贯入度来进行一系列测试，以充分调动承载力。桩安装后，静态承载力也可能随着时间的推移而减少或增加，静态和动态测试都代表了各自测试时的承载力。当使用考虑土壤强度随时间变化的动态重击试验时，测量的极限轴向静态压缩能力和动态试验估计值之间的相关性通常会得到改善（见 6.8 ). 注2: 虽然动态测试分析的解释可能提供桩的抗拉（抗拔）能力的估计，但本标准的用户应谨慎地解释从单个动态测量位置的分析中估计的侧阻力，并避免对嵌入长度小于10m的桩进行抗拉能力估计。（嵌入桩趾附近的其他传感器也可能有助于提高抗拉能力估计。）如果工程师之前没有足够的经验来分析特定场地和桩类型的抗拉能力的动态测试数据，则根据测试方法进行静载荷测试 D3689 应用于验证张力能力估计。试验方法 D3689 提供了静态张力容量的直接和更可靠的测量。 注3: 该测试方法产生的结果质量取决于执行该测试的人员的能力，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。本测试方法的用户应注意遵守实践 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 This dynamic test method covers the procedure for applying an axial impact force with a pile driving hammer or a large drop weight that will cause a relatively high strain at the top of an individual vertical or inclined deep foundation unit, and for measuring the subsequent force and velocity response of that deep foundation unit. While in this standard force and velocity are referenced as “measured,” they are typically derived from measured strain and acceleration values. High-strain dynamic testing applies to any deep foundation unit, also referred to herein as a “pile,” which functions in a manner similar to a driven pile or a cast-in-place pile regardless of the method of installation, and which conforms with the requirements of this test method. 1.2 This standard provides minimum requirements for dynamic testing of deep foundations. Plans, specifications, or provisions (or combinations thereof) prepared by a qualified engineer may provide additional requirements and procedures as needed to satisfy the objectives of a particular test program. The engineer in responsible charge of the foundation design, referred to herein as the “Engineer”, shall approve any deviations, deletions, or additions to the requirements of this standard. 1.3 The proper conduct and evaluation of high-strain dynamic tests requires special knowledge and experience. A qualified engineer should directly supervise the acquisition of field data and the interpretation of the test results so as to predict the actual performance and adequacy of deep foundations used in the constructed foundation. A qualified engineer shall approve the apparatus used for applying the impact force, driving appurtenances, test rigging, hoist equipment, support frames, templates, and test procedures. 1.4 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. The word “shall” indicates a mandatory provision, and the word “should” indicates a recommended or advisory provision. Imperative sentences indicate mandatory provisions. 1.5 Units— The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method. 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 and calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that should generally 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 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 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 a specific precautionary statement, see Note 4 . 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 ====== 4.1 This test method obtains the force and velocity induced in a pile during an axial impact event (see Figs. 1 and 2 ). Force and velocity are typically derived from measured strain and acceleration. The Engineer may analyze the acquired data using engineering principles and judgment to evaluate the integrity of the pile, the performance of the impact system, and the maximum compressive and tensile stresses occurring in the pile. FIG. 2 Typical Arrangement for High-Strain Dynamic Testing of a Deep Foundation 4.2 If sufficient axial movement occurs during the impact event, and after assessing the resulting dynamic soil response along the side and bottom of the pile, the Engineer may analyze the results of a high-strain dynamic test to estimate the ultimate axial static compression capacity (see Note 1 ). Factors that may affect the axial static capacity estimated from dynamic tests include, but are not limited to the: (1) pile installation equipment and procedures, (2) elapsed time since initial installation, (3) pile material properties and dimensions, (4) type, density, strength, stratification, and saturation of the soil, or rock, or both adjacent to and beneath the pile, (5) quality or type of dynamic test data, (6) foundation settlement, (7) analysis method, and (8) engineering judgment and experience. If the Engineer does not have adequate previous experience with these factors, and with the analysis of dynamic test data, then a static load test carried out according to Test Method D1143/D1143M should be used to verify estimates of static capacity and its distribution along the pile length. Test Method D1143/D1143M provides a direct and more reliable measurement of static capacity. Note 1: The analysis of a dynamic test will under predict the ultimate axial static compression capacity if the pile movement during the impact event is too small. The Engineer should determine how the size and shape of the pile, and the properties of the soil or rock beneath and adjacent to the pile, affect the amount of movement required to fully mobilize the static capacity. A permanent net penetration of as little as 2 mm per impact may indicate that sufficient movement has occurred during the impact event to fully mobilize the capacity. However, high displacement driven piles may require greater movement to avoid under predicting the static capacity, and cast-in-place piles often require a larger cumulative permanent net penetration for a series of test blows to fully mobilize the capacity. Static capacity may also decrease or increase over time after the pile installation, and both static and dynamic tests represent the capacity at the time of the respective test. Correlations between measured ultimate axial static compression capacity and dynamic test estimates generally improve when using dynamic restrike tests that account for soil strength changes with time (see 6.8 ). Note 2: Although interpretation of the dynamic test analysis may provide an estimate of the pile's tension (uplift) capacity, users of this standard are cautioned to interpret conservatively the side resistance estimated from analysis of a single dynamic measurement location, and to avoid tension capacity estimates altogether for piles with less than 10 m embedded length. (Additional transducers embedded near the pile toe may also help improve tension capacity estimates.) If the Engineer does not have adequate previous experience for the specific site and pile type with the analysis of dynamic test data for tension capacity, then a static load test carried out according to Test Method D3689 should be used to verify tension capacity estimates. Test Method D3689 provides a direct and more reliable measurement of static tension capacity. Note 3: The quality of the result produced by this test method 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 test method 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.