"This study presents a new semi-empirical approach for predicting the saturated hydraulic conductivity of noncohesive (granular) soils through a constriction size-based technique. For the same particle-size distribution of a granular filter material, there can be many different void distributions depending on the as-compacted density. Therefore, particle-size distribution is not unique in determining the hydraulic conductivity as proposed in numerous earlier studies. In contrast, the constriction-size distribution is unique for a given as-placed density of the material, and therefore it is a better representation of hydraulic conductivity as proposed in this study. Accordingly, the hydraulic conductivity of a granular medium can be represented by an empirical power function that has been established on the basis of 60 laboratory tests."
Available at: http://works.bepress.com/crujikiatkamjorn/136/