1.1 本试验方法涵盖了使用2.3 kg[5-lbm]落锤下落508确定动态圆锥贯入仪所需落锤数的程序 毫米[20英寸]在压实的回填土中渗透一定深度。 1.2 该设备用于细粒和粗粒土壤、粒状材料以及用于路基、基层和回填压实的弱稳定或改性材料的压实验证，以及浅深度受限路堑和沟槽中的回填压实。 1.3 本试验方法不适用于高度稳定和胶结材料或含有大量大于37 mm骨料的颗粒材料[1]。 5英寸。]。 1.4 该方法取决于了解现场含水量，以及用户已执行校准测试以确定各种压实水平和含水量的锥贯入阻力。 1.5 单位- 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值不一定是精确的等价物；因此，为确保符合本标准，每个系统应独立使用，且两个系统的值不得组合。 在本标准文本中，先出现国际单位制，然后是括号中的英寸-磅[或其他非国际单位制]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标准。 1.6 工程专业中的常见做法是同时使用磅来表示质量单位[lbm]和力[lbf]。这隐含地结合了两个独立的单元系统；也就是说，绝对系统和引力系统。本标准在处理英寸时使用绝对单位制编写- 磅制。在该系统中，磅[lbf]表示力（重量）的单位。然而，使用天平或天平记录磅质量[lbm]或密度读数（lbm/ft） 3. 不应视为不符合本标准。 1.7 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 . 1.8 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 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 该试验方法用于评估压实材料的压实力。将圆锥体驱动83 mm[3]距离所需的滴数。 25英寸。]用作根据土壤压实度确定合格或不合格的标准。 5.2 该装置不直接测量土壤压实度，需要确定已知压实度和含水量的类似土壤中的滴落数和压实度之间的相关性。 5.3 滴数取决于土壤含水量。装置的校准应在等于现场预期含水量的含水量下进行。 5.4 还有其他不同尺寸、锤重、锥体尺寸和锥体几何形状的DCP。 这些设备有不同的测试方法（例如 D6951 )5-lbm DCP与土壤压实度的相关性是该装置独有的。 5.5 5-lbm DCP是一种简单的设备，能够在现场条件下由单个操作员进行操作。它通常用作施工人员在道路路面中逐层压实的质量控制（QC）、受限路堑和沟渠中的回填压实以及公用设施路面恢复工作。 注1: 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 covers the procedure for the determination of the number of drops required for a dynamic cone penetrometer with a 2.3-kg [5-lbm] drop hammer falling 508 mm [20 in.] to penetrate a certain depth in compacted backfill. 1.2 The device is used in the compaction verification of fine- and coarse-grained soils, granular materials, and weak stabilized or modified material used in subgrade, base layers, and backfill compaction in confined cuts and trenches at shallow depth. 1.3 The test method is not applicable to highly stabilized and cemented materials or granular materials containing a large percentage of aggregates greater than 37 mm [1.5 in.]. 1.4 The method is dependent upon knowing the field water content and the user having performed calibration tests to determine cone penetration resistance of various compaction levels and water contents. 1.5 Units— The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. Within the text of this standard, SI units appear first followed by the inch-pound [or other non-SI] units in brackets. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard. 1.6 It is common practice in the engineering profession to concurrently use pounds to represent both a unit of mass [lbm] and a force [lbf]. This implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. This standard has been written using the absolute system of units when dealing with the inch-pound system. In this system, the pound [lbf] represents a unit of force (weight). However, the use of balances or scales recording pounds of mass [lbm] or the reading of density in lbm/ft 3 shall not be regarded as a nonconformance with this standard. 1.7 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 . 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 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 The test method is used to assess the compaction effort of compacted materials. The number of drops required to drive the cone a distance of 83 mm [3.25 in.] is used as a criterion to determine the pass or fail in terms of soil percent compaction. 5.2 The device does not measure soil compaction directly and requires determining the correlation between the number of drops and percent compaction in similar soil of known percent compaction and water content. 5.3 The number of drops is dependent on the soil water content. Calibration of the device should be performed at a water content equal to the water content expected in the field. 5.4 There are other DCPs with different dimensions, hammer weights, cone sizes, and cone geometries. Different test methods exist for these devices (such as D6951 ) and the correlations of the 5-lbm DCP with soil percent compaction are unique to this device. 5.5 The 5-lbm DCP is a simple device, capable of being handled and operated by a single operator in field conditions. It is typically used as Quality Control (QC) of layer-by-layer compaction by construction crew in roadway pavement, backfill compaction in confined cuts and trenches, and utility pavement restoration work. Note 1: The quality of results 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 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 these factors.