This International Standard specifies methods for the laboratory determination of the water flow characteristics in soil. This International Standard is applicable to the laboratory determination of the coefficient of permeability of soil within the scope of geotechnical investigations. The permeability test is carried out on a cylindrical test specimen that is either confined laterally by a rigid container or by a flexible membrane. The specimen is subjected to differential hydraulic head and the water flow is measured under either a constant or falling head. The results are used to determine the coefficient of permeability of the soil specimen. Tests may be carried out on undisturbed, remoulded, compacted or reconstituted specimens. The calculation of coefficient of permeability assumes the application of Darcy s law for laminar flow under saturated conditions. The size of the specimen may not adequately represent the fabric features present in field conditions. NOTE This document fulfils the requirements of the determination of the coefficient of permeability of soils in the laboratory for geotechnical investigation and testing in accordance with EN 1997-1 and EN 1997-2.