Active porosity and its effect on the physical mechanical properties of clay

The definition of active porosity given by B.N. Gumenskii is revised. The active porosity is taken to mean the bulk porosity less the pore space volume occupied by adsorbed water. The methods of calculating the active porosity discussed in the paper are based on finding the adsorbed-water volume at the maximal airdry moisture of soil and subtracting this value from the bulk porosity. The active porosity is shown to be important for assessing the reservoir and infiltration soil properties and a number of other characteristics used in soil mechanics.