1.1 这些测试方法涵盖了实验室对导水率的测量（也称为 渗透系数 )在约15至30°C（59至86°F）的温度范围内，使用柔性壁渗透仪对水饱和多孔材料进行测量。可以使用此范围之外的温度；然而，用户必须确定汞和R的比重 T （参见 10.3 )在这些温度下，使用以下数据 化学和物理手册 有六种替代方法或液压系统可用于测量导水率。这些液压系统如下: 1.1.1 方法A-- 恒定的头 1.1.2 方法B-- 水头下降，尾水高程恒定 1.1.3 方法C-- 水头下降，尾水高程上升 1.1.4 方法D-- 恒定流速 1.1.5 方法E-- 恒定体积-恒定水头（水银柱） 1.1.6 方法F-- 定容——水头下降（水银柱），尾水高程上升 1.2 这些测试方法使用水作为渗透液体； 看见 4.3 和章节 6. 水需求试剂。 1.3 这些测试方法可用于导水率小于约1×10的所有试样类型（完整、重构、重塑、压实等） −6 m/s（1×10 −4 cm/s），提供以下水头损失要求 5.2.3 满足。对于定容法，导水率通常必须小于约1×10 −7 m/s。 1.3.1 如果导水率大于约1×10 −6 m/s，但不超过约1×10 −5 m/s；则液压管的尺寸需要随着多孔端件的孔隙率而增加。其他策略，如使用更高粘度的流体或适当减小试样的横截面积，或两者兼而有之，也是可能的。关键标准是第节中涵盖的要求 5. 必须得到满足。 1.3.2 如果导水率小于约1×10 −11 则标准液压系统和温度环境通常是不够的。 处理此类不透水材料时可能采取的策略包括以下内容: 一 更精确地控制温度， b 采用高精度设备进行非稳态测量，并进行严格分析以确定水力参数（根据Zhang等人的研究，这种方法缩短了测试时间）( 1. ) 2. )，以及 c 缩短试样长度或扩大试样横截面积，或两者兼而有之（考虑试样粒径 ( 2. ) ). 也可以考虑其他方法，例如使用更高的水力梯度、更低粘度的流体、消除任何可能的化学梯度和细菌生长，以及严格验证泄漏。 1.4 导水率大于1×10的材料的导水率 −5 m/s可通过试验方法确定 D2434 . 1.5 所有观察值和计算值应符合实践中确立的有效数字和四舍五入的指南 D6026 . 1.5.1 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。所使用的程序不考虑材料变化、获取数据的目的、特殊目的研究或对用户目标的任何考虑；并且通常的做法是增加或减少报告数据的有效数字以与这些考虑相称。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 本标准还包含危险部分（第 7. ). 1.7 进行此测试的时间取决于所使用的方法（A、B、C、D、E或F）、试样的初始饱和度和试样的导水率等项目。定容法（E和F）和方法D需要最短的时间- 时间。通常，可以在两到三天内使用方法D、E或F进行测试。方法A、B和C需要更长的时间，从几天到几周不等，具体取决于导水率。通常，对于1×10量级的导水率，大约需要一周的时间 –9 m/s。测试时间最终通过满足每种方法的平衡标准来控制（见 9.5 ). 1.8 单位-- 以国际单位制表示的值应被视为标准。括号中给出的英寸-磅单位是数学转换，仅供参考，不被视为标准单位，除非明确规定为标准，如0.5毫米或0.01英寸。 1.9 本标准并不旨在解决与其使用相关的所有安全问题（如果有的话）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.10 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 =====意义和用途====== 4.1 这些测试方法适用于土壤和岩石等多孔材料中的一维层流。 4.2 多孔材料的导水率通常随着材料孔隙中空气量的增加而降低。这些测试方法适用于几乎不含空气的水饱和多孔材料。 4.3 这些测试方法适用于多孔材料与水的渗透。其他液体（如化学废物）的渗透可以使用与这些测试方法中描述的程序类似的程序来实现。然而，这些测试方法仅适用于水为渗透性液体的情况。 见第节 6. . 4.4 达西定律被认为是有效的，导水率基本上不受水力梯度的影响。 4.5 这些测试方法提供了一种在受控有效应力水平下确定导水率的方法。导水率随孔隙比变化而变化，孔隙比随有效应力变化而变化。如果孔隙比发生变化，试样的导水率可能会发生变化，请参见 附录X2 为了确定导水率和孔隙比之间的关系，必须在不同的有效应力下重复导水率试验。 4.6 使用这些测试方法获得的结果与现场材料的导水率之间的相关性尚未得到充分研究。经验有时表明，在小试样上测量的导水率不一定与大尺度值相同。因此，应由合格人员谨慎地将结果应用于现场情况。 4.7 在大多数情况下，当测试高膨胀潜力材料并使用定容液压系统时，有效围压应为试样膨胀压力的1.5倍左右，或防止膨胀的应力。如果围压小于膨胀压，可能会出现异常流动条件；例如，汞柱朝着错误的方向移动。 注1: 本标准产生的结果的质量取决于执行人员的能力以及所用设备和设施的适用性。符合实践标准的机构 D3740 通常被认为有能力进行合格和客观的测试/取样/检查。可靠的结果取决于许多因素；实习 D3740 提供了一种评估其中一些（但不是全部）因素的方法。

1.1 These test methods cover laboratory measurement of the hydraulic conductivity (also referred to as coefficient of permeability ) of water-saturated porous materials with a flexible wall permeameter at temperatures between about 15 and 30°C (59 and 86°F). Temperatures outside this range may be used; however, the user would have to determine the specific gravity of mercury and R T (see 10.3 ) at those temperatures using data from Handbook of Chemistry and Physics . There are six alternate methods or hydraulic systems that may be used to measure the hydraulic conductivity. These hydraulic systems are as follows: 1.1.1 Method A— Constant Head 1.1.2 Method B— Falling Head, constant tailwater elevation 1.1.3 Method C— Falling Head, rising tailwater elevation 1.1.4 Method D— Constant Rate of Flow 1.1.5 Method E— Constant Volume–Constant Head (by mercury) 1.1.6 Method F— Constant Volume–Falling Head (by mercury), rising tailwater elevation 1.2 These test methods use water as the permeant liquid; see 4.3 and Section 6 on Reagents for water requirements. 1.3 These test methods may be utilized on all specimen types (intact, reconstituted, remolded, compacted, etc.) that have a hydraulic conductivity less than about 1 × 10 −6 m/s (1 × 10 −4 cm/s), providing the head loss requirements of 5.2.3 are met. For the constant-volume methods, the hydraulic conductivity typically has to be less than about 1 × 10 −7 m/s. 1.3.1 If the hydraulic conductivity is greater than about 1 × 10 −6 m/s, but not more than about 1 × 10 −5 m/s; then the size of the hydraulic tubing needs to be increased along with the porosity of the porous end pieces. Other strategies, such as using higher viscosity fluid or properly decreasing the cross-sectional area of the test specimen, or both, may also be possible. The key criterion is that the requirements covered in Section 5 have to be met. 1.3.2 If the hydraulic conductivity is less than about 1 × 10 −11 m/s, then standard hydraulic systems and temperature environments will typically not suffice. Strategies that may be possible when dealing with such impervious materials may include the following: (a) controlling the temperature more precisely, (b) adoption of unsteady state measurements by using high-accuracy equipment along with the rigorous analyses for determining the hydraulic parameters (this approach reduces testing duration according to Zhang et al. ( 1 ) 2 ), and (c) shortening the length or enlarging the cross-sectional area, or both, of the test specimen (with consideration to specimen grain size ( 2 ) ). Other approaches, such as use of higher hydraulic gradients, lower viscosity fluid, elimination of any possible chemical gradients and bacterial growth, and strict verification of leakage, may also be considered. 1.4 The hydraulic conductivity of materials with hydraulic conductivities greater than 1 × 10 −5 m/s may be determined by Test Method D2434 . 1.5 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026 . 1.5.1 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 be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design. 1.6 This standard also contains a Hazards section (Section 7 ). 1.7 The time to perform this test depends on such items as the Method (A, B, C, D, E, or F) used, the initial degree of saturation of the test specimen and the hydraulic conductivity of the test specimen. The constant volume Methods (E and F) and Method D require the shortest period-of-time. Typically a test can be performed using Methods D, E, or F within two to three days. Methods A, B, and C take a longer period-of-time, from a few days to a few weeks depending on the hydraulic conductivity. Typically, about one week is required for hydraulic conductivities on the order of 1 × 10 –9 m/s. The testing time is ultimately controlled by meeting the equilibrium criteria for each Method (see 9.5 ). 1.8 Units— The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are mathematical conversions, which are provided for information purposes only and are not considered standard, unless specifically stated as standard, such as 0.5 mm or 0.01 in. 1.9 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. 1.10 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 These test methods apply to one-dimensional, laminar flow of water within porous materials such as soil and rock. 4.2 The hydraulic conductivity of porous materials generally decreases with an increasing amount of air in the pores of the material. These test methods apply to water-saturated porous materials containing virtually no air. 4.3 These test methods apply to permeation of porous materials with water. Permeation with other liquids, such as chemical wastes, can be accomplished using procedures similar to those described in these test methods. However, these test methods are only intended to be used when water is the permeant liquid. See Section 6 . 4.4 Darcy's law is assumed to be valid and the hydraulic conductivity is essentially unaffected by hydraulic gradient. 4.5 These test methods provide a means for determining hydraulic conductivity at a controlled level of effective stress. Hydraulic conductivity varies with varying void ratio, which changes when the effective stress changes. If the void ratio is changed, the hydraulic conductivity of the test specimen will likely change, see Appendix X2 . To determine the relationship between hydraulic conductivity and void ratio, the hydraulic conductivity test would have to be repeated at different effective stresses. 4.6 The correlation between results obtained using these test methods and the hydraulic conductivities of in-place field materials has not been fully investigated. Experience has sometimes shown that hydraulic conductivities measured on small test specimens are not necessarily the same as larger-scale values. Therefore, the results should be applied to field situations with caution and by qualified personnel. 4.7 In most cases, when testing high swell potential materials and using a constant-volume hydraulic system, the effective confining stress should be about 1.5 times the swell pressure of the test specimen or a stress which prevents swelling. If the confining stress is less than the swell pressure, anomalous flow conditions my occur; for example, mercury column(s) move in the wrong direction. Note 1: 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 facility used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some, but not all, of those factors.