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The shrink–swell capacity of soils refers to the extent certain clay minerals will expand when wet and retract when dry. Soil with a high shrink–swell capacity is problematic and is known as shrink–swell soil, or expansive soil . [ 1 ]
Soils with smectite clay minerals, including montmorillonite and bentonite, have the most dramatic shrink–swell capacity. The mineral make-up of this type of soil is responsible for the moisture retaining capabilities. All clays consist of mineral sheets packaged into layers, and can be classified as either 1:1 or 2:1.
The London Clay Formation is a marine geological formation of Ypresian (early Eocene Epoch, c. 54-50 million years ago) [1] age which crops out in the southeast of England. The London Clay is well known for its fossil content. The fossils from the lower Eocene rocks indicate a moderately warm climate, the tropical or subtropical flora.
Properties that are influenced by soil texture include porosity, permeability, infiltration, shrink-swell rate, water-holding capacity, and susceptibility to erosion. In the illustrated USDA textural classification triangle, the only soil in which neither sand, silt nor clay predominates is called loam.
Vertisols have a high content of expansive clay minerals, many of them belonging to the montmorillonites that form deep cracks in drier seasons or years. In a phenomenon known as argillipedoturbation, alternate shrinking and swelling causes self-ploughing, where the soil material consistently mixes itself, causing some vertisols to have an extremely deep A horizon and no B horizon.
Smectite can swell because of the reversible incorporation of water and cations in the interlayer space. The TOT layers are negatively charged because of the isomorphic substitution of Si(IV) atoms by Al(III) atoms in the two external silica tetrahedral layers and because of the replacement of Al(III) or Fe(III) atoms by Mg 2+ or Fe 2+ cations ...
UK economy to shrink by 0.3% – the worst of any G7 country, as IMF warns of more turmoil. Alastair Jamieson,Jon Stone and Archie Mitchell. Updated April 12, 2023 at 4:41 AM.
Shrink–swell capacity in soil mechanics; Unload-reload constant (κ) in critical state soil mechanics This page was last edited on 6 May 2023, at ...