Hydrology of swelling soils: a review

Authors
Citation
De. Smiles, Hydrology of swelling soils: a review, AUST J SOIL, 38(3), 2000, pp. 501-521
Citations number
111
Categorie Soggetti
Environment/Ecology
Journal title
AUSTRALIAN JOURNAL OF SOIL RESEARCH
ISSN journal
00049573 → ACNP
Volume
38
Issue
3
Year of publication
2000
Pages
501 - 521
Database
ISI
SICI code
0004-9573(2000)38:3<501:HOSSAR>2.0.ZU;2-A
Abstract
A generally accepted theory of liquid flow in rigid systems has been used i n soil science for more than 50 years. Liquid flow in systems that change v olume with liquid content is not so well described and remains a major chal lenge to soil scientists, although its application in chemical and mining e ngineering and soil mechanics is increasingly accepted. Theory of water flo w in swelling soils must satisfy material continuity. It must also account for changes in the gravitational potential energy of the system during swel ling and for anisotropic stresses that constrain the soil laterally but per mit vertical movement. A macroscopic and phenomenological analysis based on material balance and Darcy's law is the most useful first approach to wate r flow and volume change in such soils. Use of a material coordinate based on the solid distribution results in a flow equation analogous to that L. A . Richards enunciated for non-swelling soils. This framework is strain-inde pendent and solutions to the flow equation exist for a wide range of practi cally important conditions. The approach has been well tested in clay suspe nsions and saturated systems such as mine tailings and sediments. It is als o applied in soil mechanics. This paper reviews central elements in applica tion of the analysis to swelling soils. It argues that, as with use of the Richards' equation in rigid soils, complexities are evident, but the approa ch remains the most coherent and profitable to support current need and fut ure research. The use of material coordinates, to ensure material balance i s assessed correctly, is simple.