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Re‐evaluation of the structural properties of some British swelling soils
Author(s) -
Groenevelt P. H.,
Grant C. D.
Publication year - 2001
Publication title -
european journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 1351-0754
DOI - 10.1046/j.1365-2389.2001.00388.x
Subject(s) - shrinkage , curvature , swelling , soil water , water content , overburden , water retention curve , void ratio , geotechnical engineering , mathematics , soil science , mineralogy , materials science , geology , water retention , geometry , composite material , statistics
Summary The structural condition of swelling soils can be assessed from their shrinkage curves. We re‐evaluated data on six British swelling soils using modern methods to model the void ratio, e , as a function of the moisture ratio, ϑ . The points on the e – ϑ curve were fitted with a constitutive shrinkage equation using an unbiased least‐squares, curve‐fitting program. The shrinkage curves were then differentiated to obtain their slopes, σ ( ϑ ), which were used to calculate the overburden potentials, Ω. The slope functions were subsequently differentiated to obtain the curvatures, κ ( ϑ ), from which the maximum curvature at the wet end was used to separate the structural shrinkage, S c , from the proportional (unsaturated) shrinkage. At the point of maximum curvature, S c and the volumetric air content, θ ac , were calculated and found to correspond closely to those reported previously. Water retention curves were constructed and fitted using the van Genuchten equation, from which the α coefficient appears an important structural parameter. The structural condition of a swelling soil appears to be well described by its air content at the point of maximum curvature, its van Genuchten α coefficient, and a parameter describing the effect of the overburden potential.