On the rheology of rock creep

Abstract

On the Rheology of Rock Creep The standard (linear) rheological models and the experimental evidence on rock creep are reviewed and it is shown that a new rheological equation (“stress-strain relation”) must be found to describe the most common behavior of rocks. Such a rheological equation is deduced by a correspondence principle with a Kelvin material and is presented. It is nonlinear and of the form: $$\sigma ' = 2\eta \ddot \varepsilon + \beta \dot \varepsilon ^2 $$ wheree is shear strain,σ shear stress, dot denotes time derivation, andη andβ are constants. Some consequences of this equation are discussed.