AASHTO T 215-22

This method describes a procedure for the determination of the permeability of water through granular (cohesionless) soils in a steady-state condition.

The determination of the coefficient of permeability, k, as defined in this method, was developed under the assumptions of the validity of Darcy’s Law, which states that the coefficient of permeability is the ratio of the flow rate to the hydraulic gradient.

This test procedure is intended for use with disturbed granular soils containing less than 10 percent by mass of the material passing the 75-μm (No. 200) sieve. Soil materials with greater than 10 percent by mass of the material passing the 75-μm (No. 200) sieve are subject to consolidation effects that may influence the outcome of the test results. Permeability of fine-grained and cohesive soils should be performed by use of a flexible wall permeameter test procedure, such as ASTM D5084.

Two methods of test, Method A and Method B, are provided. The method used is dependent on the permeameter used to complete testing.