Verification and Implementation of a Creep Model Considering the Duvaut-Lion Overstress Function - Mining, Metallurgy & Exploration (2021)

The increase in depth of mines due to the depletion of surface deposits leads to unsafe tunnel construction and overall ore extraction. This is due to tunnel instability associated with the surrounding rock mass’s ability to exhibit creep that occurs over time. However, the explicit description of this mechanism using conventional constitutive models has proven to be difficult and inadequate. Hence, this paper presents an integrated viscoelastic viscoplastic visco-damage model with the Duvaut-Lions function. The presented model is calibrated by experimental data to determine the viscoelastic viscoplastic and visco-damage parameters. It is further implemented in a finite volume numerical code and verified on an experimental scale by numerical modeling of a cylindrical specimen. It describes the 3-phase creep mechanism perfectly as compared to the inbuilt conventional integer-order derivative model. Results from the conducted verification show that it can successfully be employed to describe the long-term behavior associated with the creep mechanism.