Several concrete faced rockfill dams in the world present cracks in the concrete face. In this paper the authors make an attempt to predict formation of cracks in one of such dams, the Mohale dam in Lesotho, South Africa. Foundation of the dam, dam body and the concrete slab are modelled in 3D. A Mohr-Coulomb plasticity model with hardening is adopted for the rockfill. Contact between the concrete face and rockfill is modelled with contact elements, with a Coulomb friction material constitutive model. Interface elements are used to model the vertical joints among the 37 panels that form the concrete face. For the concrete face a total strain crack model in combination with crushing is adopted. In the analysis the different construction stages have been considered, as well as the different impoundment stages. The results shown in this paper are displacement and stresses in the rockfill and the concrete face, crack patterns and crack strains in the concrete face, and openings of the vertical joints.
