Modeling coupled processes of non-steady seepage flow and non-linear deformation for a concrete-faced rockfill dam

A coupled non-linear elastic deformation and non-steady seepage flow model was established for performance assessment of the concrete-faced rockfill (CFR) dams. The deformation behaviors of the rockfills and the soil–structure interfaces were modeled with the Duncan–Chang model and Desai’s thin-layer elements, respectively. The seepage flow process was characterized with a newly-developed parabolic variational inequality formulation of the Signorini’s condition. The deformation-dependent permeability of the rockfills was characterized by a calibrated Kozeny–Carman model that considered the influence of confining pressure on porosity. The proposed model was applied to capture the seepage flow and deformation behaviors of the Shuibuya CFR dam in China.