Influence of soil water on stress-strain behaviour of a compacting soil in semi-arid Kenya

摘要: Abstract Depending on the top and subsoil textures, semi-arid soils exhibit cohesive frictional properties that are associated with relatively high soil strength, bulk density penetration resistance. The objective of this study was to gain knowledge mechanical compacting chromic luvisols in order improve design tillage tools. Therefore, we applied critical state mechanics stress–strain behaviour using triaxial tests under laboratory conditions. Field investigations involved random collection undisturbed samples which were subjected testing first by isotropic consolidation compression then shearing. Plots deviatoric stress against axial strain made determine shear strengths at states over different water levels two depths 0–20 cm for plough 20–40 cm hard pan layers, respectively. An exponential model used fit stress–axial test data accurately predicted trends. Soil significantly influenced cohesion (c′) internal angle friction (ϕ′) hence luvisols. regression equations developed showed c′ ϕ′ have quadratic relationships water. very clay bonding strength (hard pan) layer resulted resistance values layer. increase decreasing content affected between upper lower plastic limits sandy soil. Thus, as dried, ceased behave (ductile flow) manner thus began break apart crumble. crumbling indicative brittle failure. transition stage from an a decrease occurred range 6–10%. Knowledge is practical significance appropriate tools specific type.