Estimating Porosity and Particle Size for Hydraulic Conductivity of Binary Mixed Soils Containing Two Different-Sized Silica Particles

Abstract

This study investigates the hydraulic conductivity (K) of binary mixed soils containing two different-sized silica particles, with the ultimate goal of developing the porosity (n) and equivalent particle size (deq) estimating formulas for binary mixed soils. Theoretical backgrounds for K of mixed soils were reviewed. In addition, a series of constant head permeameter tests for mixtures with three different size ratios between small and large particles were performed. It is demonstrated that the K of tested materials decreases with an increase in volume fraction of small particles (SCV) when SCV<SCV* (volumetric critical small particle content) because of the decreases in both n and deq. In contrast, when SCV>SCV*, K shows less change with SCV because of the offset mechanism between increased n and decreased deq. Additionally, n and deq estimating methods for mixed soils are suggested in this study and compared with the experimental results.