Abstract：Long-term strength is crucial for studying the time-dependent mechanical properties of deep engineering rock masses. Based on the anisotropic time-dependent fracture characteristics of hard rock induced by true triaxial stresses，the steady-state creep rate method for determining the long-term strength of Jinping marble was proposed in this paper，in which the stress when the steady-state creep rates in the directions of and are equal is determined as the long-term strength of the rock. In addition，the long-term strength of Jinping marble was calculated by the isochronous curve method，the transition creep method，and the steady-state creep rate method，respectively. The results show that transition creep method is not suitable for solving the long-term strength of Jinping marble under true triaxial stress. It also shows that the isochronous curve method can only obtain the long-term strength range of Jinping marble under true triaxial stress and its accuracy relies on the stress increment selected by multistage creep loading. And the long-term strength of Jinping marble under true triaxial stresses can be accurately obtained by steady-state creep rate method，which proves the correctness and reliability of this method.
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2023, Vol. 42 
