ASTM D5567-94 (2018) pdf free.Standard Test Method for Hydraulic Conductivity Ratio (HCR) Testing of Soi Geotextile System.
This test method presents a procedure for performingpermeability tests of soil/geotextile systems.The techniquerequires placement of the soil and geotextile in a flexiblewallpermeameter.The soil/geotextile specimen is saturated using de-airedwater and back-pressure techniques.The specimen is consoli-dated at the effective stress anticipated in the proposed appli-cation.The sample is then permeated with water. The hydraulicconductivity of the soil/geotextile specimen is measured andplotted as a function of elapsed time and volume of waterpassing through the sample.The hydraulic conductivity mayeither increase or decrease during the test，depending on thebehavior of the geotextile filter. The test is terminated when astabilized hydraulic conductivity is obtained,or when thehydraulic conductivity decreases below the minimum valueallowed by the drainage design.
This test method applies to the permeation of porousmaterials with water. Permeation with other liquids，such aschemical wastes, can be accomplished using procedures simi-lar to those described in this test method. However，this testmethod is intended to be used only when water is the permeantliquid.
The mathematical concepts (primarily Darcy’s law)used in this test method were originally developed for one-dimensional，laminar flow of water within porous materials,which is often the case with soil and geotextiles. When flowconditions are laminar and one-dimensional，the hydraulicconductivity is unaffected by hydraulic gradient. However,when flow occurs through some soil/geotextile systems,achange in hydraulic gradient could cause movement of soilparticles, thereby changing the structure of the test specimenand hence,changing the hydraulic conductivity of the soil/geotextile system. The mathematical expressions given byDarcy’s law are still appropriate for application to this situa-tion; however，it is therefore imperative that the hydraulicgradient be controlled carefully in the HCR test to simulatefield conditions.This test method provides a means of determininghydraulic conductivity at a controlled level of effective stress.Hydraulic conductivity varies with void ratio,which in turnvaries with effective stress. The hydraulic conductivity of thetest specimen will probably change if the void ratio is changed.lt is therefore imperative that the effective stress (that is, theeffective confining pressure) be controlled carefully in theHCR test to simulate field conditions.ASTM D5567 pdf download.