Plasticity and Creep of Cohesive Medium

Abstract

Due to their internal friction, cohesive soils have different resistance to tension and compression, which should be taken into consideration when examining their rheological equation of state. The existing theories of plasticity and creep are based on the conception that the change in the shape of a material depends only upon the stress deviator, while the change in its volume depends only upon the hydrostatic pressure, that is

$$ {{\sigma}_{i}}=\varphi({{\varepsilon}_{i}})and\sigma={{\varphi}^{*}}\left(\varepsilon\right), $$

(1)

where σ_i and ε_i — intensity of tangent stresses and intensity of shearing strain, while σ and ε — average normal (hydrostatic) pressure and average (volumetric) deformation.