Standard Practice for Measuring Field Infiltration Rate and Calculating Field Hydraulic Conductivity Using the Modified Philip Dunne Infiltrometer Test

Importancia y uso:

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.

Subcomité:

D18.04

Volúmen:

04.09

Número ICS:

13.080.99 (Other standards related to soil quality), 65.060.35 (Irrigation and drainage equipment)

Palabras clave:

hydraulic conductivity; infiltration rate; infiltrometer; in situ testing;