1.1 本指南涵盖了计算 现场 等效层弹性模量可用于路面评估、修复和加铺层设计。根据挠度数据计算得出的等效弹性模量取决于方法，并表示在特定试验载荷和频率、温度以及其他环境和现场特定条件下，特定无损挠度试验（NDT）设备下各层的刚度。设计负荷、参考温度和其他设计的调整- 本指南未涵盖相关因素。本指南的目的不是推荐一种特定方法，而是概述估算 现场 路面层的弹性模量。 1.2 本指南适用于柔性路面和某些情况下的刚性路面（即内部板荷载），但仅限于使用分层弹性理论 2. 作为分析方法。应注意的是，各种可用的分层弹性计算机建模技术使用不同的假设和算法，结果可能会有很大差异。 可以使用其他分析程序，如有限元建模，但需要对程序进行修改。 注1: 如果需要其他分析方法，脚注3中列出的报告可以提供一些指导。 1.3 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。 1.4 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。 3. 1.5 本指南提供了有组织的信息收集或一系列选项，并不推荐具体的行动方案。本文件不能取代教育或经验，应与专业判断一起使用。并非本指南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。 1.6 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 本指南旨在介绍从挠度测量中估算层模量的方法要素，该方法可用于路面评估或覆盖层设计。为了表征路面结构各层中的材料，在实验室测量并用于某些加铺层设计程序的一个基本输入参数是弹性模量。挠度分析提供了一种技术，可用于估计 现场 路面结构的等效层弹性模量，而不是在实验室测量小样本和有时扰动样本的弹性模量。对于许多基于分层弹性理论的叠加设计程序，弹性模量近似于该等效层弹性模量，因为等效模量被确定为整个层的平均值 现场 实际路面的应力条件。 5.2 应强调的是，使用本程序计算的层模量适用于特定荷载条件和测试时的环境条件。 对于将用于路面评估和覆盖层设计的这些模量，可能需要调整参考温度、季节和设计荷载。这些调整不是本指南的一部分。 5.3 解决方案中使用的基本假设是，在特定荷载条件（幅值和面积）和温度条件下，存在一组具有代表性的层模量，因此理论或计算的弯沉盆（使用准静态分层弹性理论和无损检测装置的假设静荷载特性）非常接近测量的弯沉盆。 实际上，取决于程序中允许的公差以及与挠度传感器数量相比的相对层数，模数的几种组合可能会导致两个水池合理地“匹配”（或在公差范围内）。需要一定程度的工程判断来评估这些替代解决方案，并选择最适用的组合或消除不合理的解决方案，或两者兼而有之。 5.4 有几项研究比较了各种类型设备和分析方法的结果； 不幸的是，已经注意到了相当大的可变性。目前，尚未从使用不同“已知”材料和层厚度的统计设计的一系列测试中获得精度估计。反算结果因分析中用于模拟实际情况的各种假设以及用于产生和测量挠度的技术而显著不同。由于本指南涉及计算机化分析方法，如果输入数据和参数保持不变，则重复性良好。 目前无法确定程序的偏差。“真实”的身份 现场 基于弹性模量测试或其他现场或实验室测试的模量需要标准化，才能确定方法的偏差。

1.1 This guide covers the concepts for calculating the in situ equivalent layer elastic moduli can be used for pavement evaluation, rehabilitation, and overlay design. The resulting equivalent elastic moduli calculated from the deflection data are method-dependent and represent the stiffnesses of the layers under a specific nondestructive deflection testing (NDT) device at that particular test load and frequency, temperature, and other environmental and site-specific conditions. Adjustments for design load, reference temperature, and other design-related factors are not covered in this guide. The intent of this guide is not to recommend one specific method, but to outline the general approach for estimating the in situ elastic moduli of pavement layers. 1.2 This guide is applicable to flexible pavements and in some cases, rigid pavements (that is, interior slab loading), but is restricted to the use of layered elastic theory 2 as the analysis method. It should be noted that the various available layered elastic computer modeling techniques use different assumptions and algorithms and that results may vary significantly. Other analysis procedures, such as finite element modeling, may be used, but modifications to the procedure are required. Note 1: If other analysis methods are desired, the report listed in Footnote 3 can provide some guidance. 1.3 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. 1.4 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. 3 1.5 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide 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. 1.6 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 guide is intended to present the elements of an approach for estimating layer moduli from deflection measurements that may then be used for pavement evaluation or overlay design. To characterize the materials in the layers of a pavement structure, one fundamental input parameter measured in the laboratory and used by some overlay design procedures is the resilient modulus. Deflection analysis provides a technique that may be used to estimate the in situ equivalent layer elastic moduli of a pavement structure as opposed to measuring the resilient moduli in the laboratory of small and sometimes disturbed samples. For many overlay design procedures that are based on layered elastic theory, the resilient modulus is approximated by this equivalent layer elastic modulus, because the equivalent modulus is determined as an average value for the total layer at the in situ stress conditions of an actual pavement. 5.2 It should be emphasized that layer moduli calculated with this procedure are for a specific loading condition and for the environmental conditions at the time of testing. For these moduli to be used in pavement evaluations and overlay design, adjustments to a reference temperature, season, and design load may be required. These adjustments are not a part of this guide. 5.3 The underlying assumption used in the solution is that a representative set of layer moduli exists for the particular loading condition (magnitude and area) and temperature condition, such that the theoretical or calculated deflection basin (using quasi-static layered elastic theory and the assumed static load characteristics of the NDT device) closely approximates the measured deflection basin. In reality, depending on the tolerance allowed in the procedure and the relative number of layers compared to the number of deflection sensors, several combinations of moduli may cause the two basins to “match” (or be within tolerance) reasonably well. A certain degree of engineering judgement is necessary to evaluate these alternative solutions and select the most applicable combination or eliminate unreasonable solutions, or both. 5.4 There have been several studies that compared the results of various types of equipment and analysis methods; unfortunately, considerable variability has been noted. At this time, no precision estimate has been obtained from a statistically designed series of tests with different “known” materials and layer thicknesses. The back-calculated results do vary significantly with the various assumptions used in analysis to emulate the actual condition, as well as with the techniques used to produce and measure the deflections. Since the guide deals with a computerized analytical method, the repeatability is excellent if the input data and parameters remain the same. The bias of the procedure cannot be established at this time. The identity of the “true” in situ modulus, based on resilient modulus testing or some other field or laboratory test, needs to be standardized before the bias of the method can be established.