1.1本试验方法包括使用橡胶气球装置测定压实或牢固结合土壤的就地密度和单位重量。 1.2本试验方法适用于由细粒土或粒状土建造的压实填土或路堤的验收方法，无明显数量的岩石或粗材料。 1.3本试验方法也可用于测定原状土或原位土的原地密度和单位重量，前提是土壤在试验期间施加的压力下不会变形。 1.4本试验方法不适用于在本试验期间施加的压力下会变形的有机、饱和或高塑性土壤。本试验方法在使用时可能需要特别小心( 1. )由未粘结颗粒材料组成的土壤，不会在小孔中保持稳定侧( 2. )土壤中含有大量超过37.5 mm（1）的粗物质 ½ 英寸），( 3. )具有高孔隙比的颗粒土，或( 4. )填充含有尖锐边缘颗粒的材料。对于颗粒含量超过37的土壤。 5毫米（1 1. / 2. 英寸），试验方法D 4914或D 5030 应使用。 1.5以国际单位制表示的数值应视为标准。括号中给出的值仅供参考。 1.5.1在工程专业中，除非涉及动态计算，否则通常交替使用表示质量和力的单位。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。在一个标准中结合使用两套独立的英寸-磅单位在科学上是不可取的。 本标准是在处理英寸-磅系统时使用重力单位制编写的。在该系统中，磅（lbf）表示力（重量）的单位。然而，在SI系统中给出了转换。使用天平或天平记录磅质量lbm/ft 3. 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施规程D 6026中建立的有效数字和舍入准则 除非被本标准取代。 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的任何考虑因素 ’ s目标；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和健康实践，并确定监管限制的适用性。 ====意义和用途====== 本试验方法可用于测定天然无机土壤沉积物、土壤骨料混合物或其他类似硬质材料的就地密度和单位重量。它通常用作将土料压实至规定密度或由试验方法（如试验方法D 698）确定的最大密度百分比的验收依据 ，D 1557 或D 4253 . 试验方法D 698 和D 1557 要求将实验室压实试样的质量测量值精确到1g，以便计算的含水量和密度可以分别报告到三位和四位有效数字。本标准是一个现场程序，要求质量测量精确到5g。因此，含水量计算只应报告到两个有效数字，密度应报告到三个有效数字。 本试验方法可用于确定土堤、道路填料和结构回填施工中使用的压实土壤的密度和单位重量。 该试验方法通常用作验收压实至规定密度或最大密度百分比或单位重量的土壤的依据，由标准试验方法确定。 本试验方法的使用通常仅限于非饱和条件下的土壤，不建议用于软土或易变形的土壤。在试验期间施加压力期间，此类土壤可能会发生体积变化。本试验方法可能不适用于含有碎石碎片或可能刺穿橡胶膜的锐边材料的土壤。 笔记 1-尽管本试验方法中包含精度和偏差声明，但本试验方法的精度取决于执行人员的能力以及所用设备和设施的适用性。符合实践D 3740标准的机构 通常认为能够胜任和客观测试。本试验方法的使用者应注意遵守实施规程D 3740 本身不能确保可靠的测试。可靠的测试取决于许多因素；实践D 3740 提供了一种评估其中一些因素的方法。

1.1 This test method covers the determination of the in-place density and unit weight of compacted or firmly bonded soil using a rubber balloon apparatus. 1.2 This test method is suitable for use as a means of acceptance for compacted fill or embankments constructed of fine-grained soils or granular soils without appreciable amounts of rock or coarse material. 1.3 This test method also may be used for the determination of the in-place density and unit weight of undisturbed or in situ soils, provided the soil will not deform under the pressures imposed during the test. 1.4 This test method is not suitable for use in organic, saturated, or highly plastic soils that would deform under the pressures applied during this test. This test method may require special care for use on ( 1 ) soils consisting of unbonded granular materials that will not maintain stable sides in a small hole, ( 2 ) soils containing appreciable amounts of coarse material in excess of 37.5 mm (1 ½ in.), ( 3 ) granular soils having high void ratios, or ( 4 ) fill materials containing particles with sharp edges. For soils containing appreciable amounts of particles in excess of 37.5 mm (1 1 / 2 in.), Test Methods D 4914 or D 5030 should be used. 1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.5.1 In the engineering profession it is customary to use units representing both mass and force interchangeably, unless dynamic calculations are involved. This implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. This standard has been written using the gravitational system of units when dealing with the inch-pound system. In this system the pound (lbf) represents a unit of force (weight). However, conversions are given in the SI system. The use of balances or scales recording pounds of mass lbm/ft 3 should not be regarded as nonconforming with this test method. 1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D 6026 unless superseded by this standard. 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; 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. 1.7 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 ====== This test method can be used to determine the in-place density and unit weight of natural inorganic soil deposits, soil-aggregate mixtures, or other similar firm materials. It is often used as a basis of acceptance for earthen material compacted to a specified density or percentage of a maximum density determined by a test method, such as Test Methods D 698 , D 1557 or D 4253 . Test Methods D 698 and D 1557 require that mass measurements of laboratory compacted test specimens be determined to the nearest 1 g so that computed water contents and densities can be reported to three and four significant digits, respectively. This standard is a field procedure requiring mass measurements to the nearest 5 g. As such, water content calculations should only be reported to two significant digits and density to three significant digits. This test method may be used to determine the density and unit weight of compacted soils used in construction of earth embankments, road fill, and structural backfill. This test method often is used as a basis of acceptance for soils compacted to a specified density or a percentage of maximum density or unit weight, as determined by a standard test method. The use of this test method is generally limited to soil in an unsaturated condition and is not recommended for soils that are soft or that deform easily. Such soils may undergo a volume change during the application of pressure during testing. This test method may not be suitable for soils containing crushed rock fragments or sharp edge materials which may puncture the rubber membrane. Note 1—Notwithstanding the statements on precision and bias contained in this test method, the precision of this test method is dependent on the competence of the personnel performing it and the suitability of the equipment and the facilities used. Agencies that meet the criteria of Practice D 3740 are generally considered capable of competent and objective testing. Users of this test method are cautioned that compliance with Practice D 3740 does not in itself ensure reliable testing. Reliable testing depends on many factors; Practice D 3740 provides a means of evaluating some of those factors.