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Strength and deformation of agricultural soil: measurement and practical significance
Author(s) -
Kirby J. M.
Publication year - 1991
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/j.1475-2743.1991.tb00878.x
Subject(s) - consolidation (business) , geotechnical engineering , deformation (meteorology) , compaction , tillage , compressive strength , soil water , shear stress , stress (linguistics) , shear (geology) , soil structure , geology , environmental science , soil science , materials science , composite material , petrology , accounting , ecology , linguistics , oceanography , philosophy , business , biology
. Soil has a finite strength to resist permanent volume change and permanent shear deformation. When the stresses imposed on the soil are of a sufficient magnitude to overcome the strength, then the deformation falls into one of two regimes. At low stress ratios (ratio of normal stress to maximum past stress) the soil expands when sheared and at high stress ratios it compresses. The maximum past stress in a field soil is the pre‐consolidation stress. The pre‐consolidation stress is the compressive stress greater than which compression is considerable and permanent. These regimes of soil deformation behaviour are consistent and predictable under a wide range of conditions. They are described by the critical state concept, which can usefully be applied to soil management. Management decisions can be based on whether the stresses imposed by a particular operation result in high or low stress ratios. This governs whether the soil will deform permanently or not (for compaction damage), expand on shear (tillage) or compress on shear (preparation of rice paddy soils). The change in permeability and structure can also be predicted from the deformation regime.