1.1 本规程描述了使用改进的Philip Dunne（MPD）渗透仪现场测量液体（通常是水）渗入土壤的速度的程序。然后使用现场测量的数据计算现场导水率。土壤应被视为天然存在的细粒或粗粒土壤或加工材料或天然土壤和加工材料的混合物，或其他多孔材料，且基本不溶，符合 5.1 . 1.2 根据需要渗透速率的条件，可在地面或坑内、裸土上或有植被的给定深度进行此操作。 然而，当试验表面位于地下水位、高位地下水位或毛细管边缘处或其下方时，不能进行该实践。 1.3 本规程适用于在中定义的渗透速率范围内的土壤 5.1 ，只要MPD渗透计底座和被测土壤之间能够充分密封。在高渗透性土壤中，可以在较短的时间间隔内读取读数，以确保收集足够的数据来确定渗透速率。 1.4 现场测量是一种落差测试，可以在适合雨水渗透实践的粉砂或粘性砂土中相对快速地进行（30到60分钟）。 它适用于测试整个场地的多个位置，以表征整个场地渗透速率的空间变异性。 1.5 现场测量可用于测量渗透率，可用于计算现场导水率。现场水力传导率可作为一项指标，用于比较土壤在地面排水应用开发中的适用性（例如，雨水花园或雨水填充）。 1.6 单位- 以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 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。 1.9 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。 1.10 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 本规程仅适用于渗透速率为2.5 mm/h（现场渗透系数为6.9）的土壤 × 10 -7 m/s）至15000 mm/h（现场导水率为4.0 × 10 -3 米/秒）。 5.2 本规程适用于土壤入渗速率的现场测量和现场渗透系数的计算。它最初是为雨水处理应用而开发的，并已用于设计、验证施工以及对地面排水应用（如雨水花园或雨水收集系统）进行年度测试 ( 1. ) . 其他合适的应用包括评估潜在的败血症- 储罐处理场（ASTM D5879 和 D5921 )，淋洗和排水效率，灌溉要求，侵蚀潜力，林业，农业，水传播和补给，以及其他应用。本试验不适用于液压屏障/密封件，如垃圾填埋场衬垫、核废物储存库或大坝核心。本试验也不适用于渗透过程中体积发生变化的土壤，如湿陷性或膨胀性土壤。 5.3 只有在已知水力边界条件（例如水力梯度和水流横向流动的程度）或可以可靠估计这些条件时，才能计算现场水力传导率。 注1: 本标准产生的结果的质量取决于执行该标准的人员的能力，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。 5.4 已经为该测试开发了一个数学分析，该分析遵循绿色- 假设体积含水量和湿润锋深度之间存在关系的Ampt分析，其中湿润锋处的体积含水量剖面由地面初始值和饱和土壤初始值之间的急剧过渡表示，即孔隙度 ( 1. ) , ( 2. ) . 5.5 影响入渗速率的因素很多，例如土壤结构、土壤分层、土壤表面状况、土壤饱和度、土壤和施用液体的化学和物理性质、施用液体的水头、液体的温度以及环的直径和嵌入深度。 因此，在同一地点进行的试验不太可能得出相同的结果，本标准中所述实践测量的速率主要用于比较。

1.1 This practice describes a procedure for field measurement of the infiltration rate of liquid (typically water) into soils using the modified Philip Dunne (MPD) infiltrometer. The data from the field measurement is then used to calculate the field hydraulic conductivity. Soils should be regarded as natural occurring fine or coarse-grained soils or processed materials or mixtures of natural soils and processed materials, or other porous materials, and which are basically insoluble and are in accordance with requirements of 5.1 . 1.2 This practice may be conducted at the ground surface or at given depths in pits, on bare soil or with vegetation in place, depending on the conditions for which infiltration rates are desired. However, this practice cannot be conducted where the test surface is at or below the groundwater table, a perched water table, or the capillary fringe. 1.3 This practice is for soils within a range of infiltration rate range defined in 5.1 , as long as an adequate seal can be made between the MPD Infiltrometer base and the soil being tested. In highly permeable soils, readings can be taken at shorter intervals, to ensure that enough data are collected to determine the infiltration rate. 1.4 The field measurement is a falling head test that can be performed relatively quickly (30 to 60 minutes) in silty sand or clayey sand soils suitable for stormwater infiltration practices. It is suitable for testing several locations across a site, to characterize the spatial variability of the infiltration rate throughout the site. 1.5 The field measurement can be used to measure the infiltration rate, which can be used to calculate the field hydraulic conductivity. The field hydraulic conductivity can be used as an index to compare the suitability of soils for use in the development of surface drainage applications (for example, rain gardens or stormwater fills). 1.6 Units— The values stated in SI units are to be regarded as the standard. No other units of measurement are to be included in 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 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; 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 analytical methods for engineering design. 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 ====== 5.1 This practice shall only be used on soils having infiltration rates ranging from 2.5 mm/h (field hydraulic conductivity of 6.9 × 10 -7 m/s) to 15000 mm/h (field hydraulic conductivity of 4.0 × 10 -3 m/s). 5.2 This practice is useful for field measurement of the infiltration rate and calculation of field hydraulic conductivity of soils. It was initially developed for stormwater treatment applications, and has been used to design, verify the construction of, and perform annual testing on surface drainage applications such as rain gardens or storm water collection systems ( 1 ) . Other suitable applications include evaluation of potential septic-tank disposal fields (ASTM D5879 and D5921 ), leaching and drainage efficiencies, irrigation requirements, erosion potential, forestry, agriculture, and water spreading and recharge, among other applications. This test is not intended for use in hydraulic barriers/seals such as landfill liners, nuclear waste repositories, or the core of a dam. This test is also not intended for use in soils that experience changes in volume during infiltration, such as collapsible or expansive soils. 5.3 Field hydraulic conductivity can only be calculated when the hydraulic boundary conditions are known, such as hydraulic gradient and the extent of lateral flow of water, or these can be reliably estimated. 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 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 those factors. 5.4 A mathematical analysis has been developed for this test that follows the Green-Ampt analysis that assumes a relationship between the volumetric water content and the depth of the wetting front, in that volumetric water content profile at the wetting front is represented by a sharp transition between the initial value in the ground and that of saturated soil, that is, the porosity ( 1 ) , ( 2 ) . 5.5 Many factors affect the infiltration rate, for example the soil structure, soil layering, condition of the soil surface, degree of saturation of the soil, chemical and physical nature of the soil and of the applied liquid, head of the applied liquid, temperature of the liquid, and diameter and depth of embedment of rings. Thus, tests made at the same site are not likely to give identical results and the rate measured by the practice described in this standard is primarily for comparative use.