Pore Size Distribution Index Research Articles

SOIL HYDRAULIC PROPERTIES AFFECTED BY SATURATION TECHNIQUE

Properties characterizing the hydraulic behavior of three soils were determined from drainage cycle tests using samples wetted with core test fluid by three saturation techniques: saturation under vacuum, saturation from below at atmospheric pressure and saturation from above at atmospheric pressure. Saturated permeability and pore-size distribution index were notably less for samples saturated at atmospheric pressure than for the vacuum-saturated samples. Bubbling pressure and residual saturation, on the other hand, were not affected by saturation technique. The observed dependence of saturated permeability and pore-size distribution index on saturation technique was attributed to the effect of entrapped air. In the modeling of field problems, determining the hydraulic properties of soils wetted at atmospheric pressure is advised.

Hydraulic Properties of Disturbed Soil Materials Affected by Porosity

AbstractRecently 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.