A new visco-elastoplastic model for modeling the creep behavior of soft rocks

The creep behavior of rocks significantly affects the long-term stability of underground spaces. This phenomenon becomes more remarkable in the case of soft rocks, deep underground construction, and rocks subjected to high stresses. A better understanding of the creep behavior of rocks is crucial for the analysis of the time-dependent behavior of rocks. In this study, a new creep constitutive model is proposed by replacing a Newtoniandashpot in the Burger model with the fractional derivative dashpot and introducing a visco plastic element to model the accelerated phase of rock creep. The proposed model is validated by the creep test results of soft rocks, which shows that this model can comprehensively describe rock creep characteristics. © 2024 The Author(s).