Abstract
Tempe cell with a self-developed horizontal hanging column attachment was used to measure the soil water characteristic curves (SWCCs) of granular materials initially saturated with either water or polymer solutions. For SWCCs of six poorly graded granular materials with d50 ranging from 0.04 to 0.7 mm in water, it was found that (1) as grain size decreases, air entry value increases, and matric suction (ψ) for the funicular and pendular regimes increases and that (2) steep desaturation curves over narrow ψ range in the funicular regime were observed. Air entry values obtained from the fitting parameter 1/α in van Genuchten SWCC equation fall in the boundaries calculated from the pore throat sizes in both simple cubic and face-centered cubic packings. A toroidal meniscus water model, which incorporates the measured surface tension and contact angle values between aqueous solutions and solid surfaces, was proposed for the SWCC in pendular regime and was compared to well-received numerical methods. This toroid model successfully depicts SWCC of poorly graded granular materials in water. However, SWCCs predicted by this toroid model underestimate the degree of saturation in the pendular regime for Ottawa 20–30 sands in polymer solutions. Herschel–Bulkley fluid, which is a type of non-Newtonian fluids, is postulated to increase the ψ needed to drain the polymer solution due to the nonzero shear stress intercept. In addition, it is also postulated by scanning electron microscopy and optical confocal imaging results that the rough surfaces of Ottawa 20–30 sand, which have many micron-sized "kinks", together with the possible chemical attractions, help retain the polymer solutions on the solid surfaces, or water film.
Recommended Citation
J. Cao et al., "On the Soil Water Characteristic Curves of Poorly Graded Granular Materials in Aqueous Polymer Solutions," Acta Geotechnica, vol. 13, no. 1, pp. 103 - 116, Springer, Feb 2018.
The definitive version is available at https://doi.org/10.1007/s11440-017-0568-7
Department(s)
Civil, Architectural and Environmental Engineering
Keywords and Phrases
Meniscus; Polymer solutions; Poorly graded; Sand; Soil–water characteristic curves; Toroid model
International Standard Serial Number (ISSN)
1861-1133; 1861-1125
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Springer, All rights reserved.
Publication Date
01 Feb 2018
