Abstract: To compensate for the lack of prediction models for rock creep failure time under conventional triaxial compression conditions and their low accuracy, based on the Norton creep constitutive relationship, a new rock creep failure time prediction model under conventional triaxial compression conditions is established by replacing the creep stress of Kachanov rock creep failure time function with a constant creep rate function. A method for determining the model parameters is proposed and its influencing factors are analyzed. The conventional triaxial compression creep test of sandy mudstone was carried out, and the creep failure time test data of five different types of rock were statistically analyzed to verify the rationality and accuracy of the new model. The results show that under the conventional triaxial compression conditions, the logarithm of the constant creep rate of rocks is linearly related to the logarithm of their creep failure time. The new model can weaken the adverse effects of heterogeneity between samples on the prediction results, and its applicability is more extensive compared to the prediction model established from the perspective of creep stress. The creep test results of six different types of rock are basically consistent with the prediction results of the new model, which verifies its accuracy and rationality.

Key words: rock creep, damage rate, Norton equation, creep rate, failure time