Based on previous researchers

this paper establishes a rheology model of rockfill used in the rheology analysis of concrete face rockfill dam despiting the rockfill microstructure. In this model

the instantaneous elasto-plastic deformations of rock fills are computed by the oblong-parabola two yield surface model

and considering the time effects

the time dependent visco-plastic deformations are derived from the empirical equation of hyperbolic function .The reliability of this rheology model isproved to be good after perfo rming inverse problems with deformation records in-situ .