Abstract: During the filling, impoundment and operation of a high rockfill dam, its rockfill materials usually undergo complicated stress paths, and their mechanical properties are significantly affected by anisotropy and particle breakage. In the existing deformation behavior analyses of high rockfill dams, one of the most common errors comes from the drawback of the constitutive models that are unable to sufficiently reflect these essential properties. This paper formulates anisotropic state parameters for the rockfill material and defines a reference anisotropy state parameter to replace the critical state line-based state parameter, so that the calculation of the spatial location relative to the reference state line can fully consider all the effects of anisotropy, particle breakage, and complex stress paths. Then, a generalized plastic MPZR model for rockfill materials is developed. Finally, we use this model and the finite element method to analyze the stress and deformation behaviors of the Nuozhadu high earth-rockfill dam, and verify its reliability and practicability using the calculated rockfill dam body displacements that agree well with the measurements in-situ.

Key words: rockfill material, anisotropy, particle breakage, constitutive model, high rockfill dam