Modeling of minimum void ratio for sand–silt mixtures

Abstract

Minimum void ratio or maximum packing density is an important soil property in geotechnical engineering. It correlates to the volume change tendency, the pore fluid conductivity, and the shear strength of the soil. In geotechnical engineering, it often requires to estimate the minimum void ratio for a sand–silt mixture with any amount of fines content, based only on few laboratory test results. The minimum void ratio for soil mixtures is usually estimated by methods based on, to some extent, an empirical approach, for example, the AASHTO coarse particle correction method. In this paper, based on a more fundamental approach using the concept of dominant particle network, we aim to develop a mathematical model that can predict the minimum void ratio for sand–silt mixtures with any amount of fines content. The developed model only requires two parameters for the prediction of minimum void ratios of soil mixtures with various fines contents. The developed model is evaluated by the experimental results on 33 types of soil mixtures available in the literature, including mixtures of sands (Ottawa sand, Nevada sand, Toyoura sand, Hokksund sand, etc), and silts (ATC silt, Nevada fines, crushed silica fines, grind Toyoura fines, etc). Comparisons of the results are discussed.