A time-dependent creep model for rock based on damage mechanics

摘要

A creep model based on the damage mechanics is proposed in this study to describe the three-stage creep deformation of rocks under conventional triaxial loading conditions. The proposed model has a simple form as it is based on the mechanism which assumes that the time-dependent creep behavior of rocks is solely described by the damage evolution. Verification of the proposed model against the creep tests shows that the model can reflect the three-stage creep behavior under higher stress levels as well as the elastic behavior under lower stress levels using the same model equations. The features of the proposed model include: (1) Simple mathematical form as it contains only one strain component without strain partitioning, and one set of equations to predict the creep deformation for all stress levels; and (2) The model requires only four parameters. All these features make the proposed model simple to use and easy to implement.