Abstract: In order to consider the damage effect of aging deterioration and water content weakened on the creep parameters of rock, a creep damage model is proposed, that is, the parameter correction and improvement of Nishihara model and the triaxial creep tests of basalt with different water contents are carried out. First of all, the creep regularities of rocks with different water contents are comparatively analyzed; and the mechanism of the influence of water content on the rock creep process is revealed. Secondly, in order to describe the rock creep process better, the aging deterioration effect and water content weakened effect are introduced. The damage variables and creep parameters are fitted by the experimental data. Finally, the calculated values of the model are compared with the experimental data. The results show that the initial creep value and steady creep value increase with the increase of water content. Furthermore, it is verified that the numerical calculation of the model agreed well with the experimental data by FLAC3D. The rock aging creep damage model proposed in this paper will provide a theoretical basis for the study of rock rheological properties.

Key words: creep test, damage, modified Nishihara model, aging deterioration, FLAC3D, Kelvin model, soft rock, viscosity coefficient