Prediction of Soil Equilibrium Water Content and Mineralogy Effect on Permeability Using Pore Size Distribution : Interim Report

Abstract

This is the last Interim Report on this research.Its content is well summarized by the title of the Report. The prediction techniques created in the research are much more rapid than time consuming physical measurements often now utilized.The effect of soil mineralogy on permeability was also investigated and some conclusions reached.The Final Report on this Study is also in preparation and will correlate and summarize the many findings of the several interim reports toward achievement of the objectives of the research.This report is submitted as partial fulfillment of these objectives. Natural soils and artificial mixtures of silt and kaolin were used. The natural soils were provided by researchers at the University of Illinois; they also provided the associated soil-moisture characteristic curves (as physically measured). Pore size distributions were obtained by mercury-intrusion procedures on f reeze-dried specimens .The soil-moisture characteristic curve can be used to predict soil equilibrium water content. This curve relates water content and soil suction.Instead of using the time consuming physical measurement procedures, this study created techniques to predict the curve from pore size distribution data in much less time.The effect of soil mineralogy on permeability is examined by comparing soil permeability to air and to water. Pore size distribution models can predict air permeability or water permeability but not both; this is the mineralogy effect.A correlation was effected between activity and the air to water permeability ratio; this factor is used to correct for the effect and, thus, account for it.Mineralogy (Low, 1961(Low, , 1979

Effects of Pore Size Distribution on Permeability and Frost Susceptibility of Selected Subgrade Materials

“…Task C -Examination of the Non-Permeable Porosity in a Soil (and In-Situ Equilibrium Water Content); Prapaharan (1982).…”