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The Influence of Soil Water Matric Potential on the Strength Properties of Unsaturated Soil
Author(s) -
Williams John,
Shaykewich C. F.
Publication year - 1970
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1970.03615995003400060010x
Subject(s) - water potential , water content , soil water , loam , degree of saturation , saturation (graph theory) , geotechnical engineering , soil science , environmental science , mathematics , geology , combinatorics
A study was made of the contribution that matric potential makes to effective stress and therefore the strength properties of two unsaturated soils. From an evaluation of the effective stress parameters C ' and ø', and the unconfined strength, the shear strength, effective stress, and the χ factor were estimated as a function of soil water matric potential over the range −0.59 to −15.1 bars. The strength properties of a Gretna clay increased rapidly with decreasing matric potential. In a Wellwood loam, however, the strength properties remained relatively constant over the range −0.59 to −15.1 bars. The influence of matric potential on the strength properties of an unsaturated soil can be described in terms of the contribution that matric potential makes to the effective stress operating in the soil system. A measure of the proportion of the matric potential operative in the effective stress is given by the χ factor which is related to the degree of saturation. Therefore, the influence that matric potential has on the strength of an unsaturated soil is related to the moisture retention properties of the soil. The implications arising from the contribution that matric potential makes to the strength properties of an unsaturated soil are briefly discussed in terms of soil‐plant relations.