A non-stationary model for rock creep based on Burgers model

The Burgers model could only describe the behavior of rock material before the third creep-phase.The viscous components of Burgers model are replaced by non-stationary viscous components.The modified Burgers model is also called as non-stationary Burgers model;and its creep compliance is obtained.Comparison between the results obtained from non-stationary Burgers model and the experiment shows that this model can well describe the initial attenuation creep phase,the stabilization creep phase and the speedup creep phase of the creep curve.