Abstract: Determining the incipience of accelerated creep stage of rock is still a difficulty at present. With energy dissipation rate as a control threshold, we divided the creep of rock into critical segments in consideration of creep rate to reflect the whole process of creep. By applying the Perzyna viscoelastic-plastic theory to the Cvisc element model, we established a creep constitutive model to determine the incipience of accelerated creep stage and expanded into three-dimensional scale. Furthermore, we conducted triaxial compressive creep test on sandstone to analyze creep rate change, isochronous stress-strain relation, and extract critical segment parameters. In the meantime, we collected creep test data of mudstone and frozen soft rock in previous studies. We applied the proposed model to identify the aforementioned creep test data of sandstone, mudstone, and frozen soft rock. By comparing the test data with the modelled data, we verified the rationality and applicability of the model in characterizing creep behavior. The research findings offer a novel idea for creep staging and mechanics modelling.

Key words: energy consumption, rock, control threshold, creep rate, critical segment, constitutive model