Water retention of rigid soils from a two-factor model for clay

TL;DR

This paper introduces a physical two-factor model for predicting water retention in rigid soils, based on measurable soil parameters, improving understanding of soil-water interactions in clay and sand.

Contribution

It proposes a novel physical model incorporating capillarity and shrinkage effects for rigid soils, with specific parameters like porosity and grain sizes, advancing soil water retention modeling.

Findings

Model predictions align well with experimental data for sands.

Incorporates pseudo-shrinkage effects in rigid soils.

Uses measurable parameters for accurate water retention prediction.

Abstract

Water retention is one of the key soil characteristics. Available models of soil water retention relate to the curve-fitting type. The objective of this work is to suggest a physical model of water retention (drying branch) for soils with a rigid matrix. "Physical" means the prediction based on the a priori measured or estimated soil parameters with a clear physical meaning. We rely on the two-factor model of clay that takes into account the factors of capillarity and shrinkage. The key points of the model to be proposed are some weak pseudo shrinkage that the rigid soils demonstrate according to their experimental water retention curves, and some specific properties of the rigid grain matrix. The three input parameters for prediction of soil water retention with the rigid grain matrix include inter-grain porosity, as well as maximum and minimum grain sizes. The comparison between measured and predicted sand water retention curves for four different sands is promising.