To study creep properties of thenardite,triaxial compression creep tests to thenardite specimens were carried out on the RLW-2000 rock rheology testing machine.The test results indicated that the creep strain and steady creep rate of thenardite increased with the increase of axial stress under a same confining pressure,while the deformation modulus of which in loading process decreased gradually.The creep process of thenardite had a nonlinear characteristic,and the yield strength of which decreased gradually with the increase of time.On this basis,the fractional generalized Kelvin model was established by replacing the classical viscous body in the conventional generalized Kelvin model with a fractional viscous body and simplified.Then a new creep constitutive model for rock was constructed by combining the simplified fractional generalized Kelvin model with the Heard steady creep model,and the parameters of which were inversed using the creep test data of thenardite.Fitting curves and test curves conform very well to each other,which illustrated that the new creep model can well reflect the creep properties of thenardite.
