Hydraulic Properties of Disturbed Soil Materials Affected by Porosity

Recently some hydraulic properties of porous materials have been described for use in constructing valid physical models that are easily measured and practically significant. These properties have been used to express similitude requirements for drainage of initially saturated soils. This paper describes how soil packing effects the hydraulic properties of three soil materials. Soil packing as measured by bulk density and porosity is related to bubbling pressure, poresize distribution index and permeability. With a light hydrocarbon oil as the wetting fluid the pore‐size distribution index was changed only slightly over a wide range of porosities. Permeability and bubbling pressure, on the other hand, were changed severalfold over the same range of porosities. For modeling purposes, one requirement for similitude between model and prototype is identical values of pore‐size distribution index. Evidently, bubbling pressure may be adjusted to suit the size of the model by changing the packing density without appreciably changing the pore‐size distribution index.