Gradient mechanical properties and analysis model of roller compacted concrete dam

Considering the cyclical impact of the weak layer on the deformation of a roller compacted concrete (RCC) dam, the gradient mechanical properties of RCC dams are analysed. A theoretical method is proposed to determine the thickness of the effect zone and the non-surface weak layer. Based on mechanics theory of composite materials, it is assumed that the density reduction and the elastic modulus of the concrete along the depth of the rolling layers in the RCC dam follow an exponential law. A load-bearing rheological model is established to describe the coordinating action between the weak layer and the noumenon of the RCC dam. A corresponding three-dimensional non-linear finite-element model is developed. It is shown that the physical parameters of the RCC dam, which are determined by a combination of theoretical analysis and testing, can reasonably reflect mechanical properties. The results from the developed model match the in situ observed results well. The proposed model can objectively describe the impact of a weak layer on the deformation of RCC dams.