Abstract: Based on the shear creep tests of mica-schist samples, the time and horizontal creep displacement curves under different stress conditions are obtained in this paper. The constitutive model based on the original and modified Burgers models is proposed to simulate the entire process of the shearing creep. The model parameters under various horizontal shear strain are obtained and the test data are compared with the previous fitted data. The results indicate the proposed is appropriate and reasonable. The conclusions can be used for the evaluation of the long-term stability and safety of rock mass after excavation.

Key words: Mica-Schist, Shear Creep, Modified Bugers Model, Constitutive Model, Curve Fitting