Cross-scale crack evolution analysis for face slab in concrete faced rockfill dams under strong earthquake

It is crucially important for seismic safety evaluation of high concrete faced rockfill dams (CFRDs) to accurately locate the weak area of the panel and to quantitatively assess the damage of the face slab. In this study, the cross-scale model for CFRD is established using the interface element with asymmetric nodes and Quadtree for refined simulation of slab and cushion interaction. The cohesive zone model for concrete, the generalized plastic model for rockfill and the state-dependent elasto-plastic interface model are combined and used to describe the strong nonlinearity and failure process. On the above basis, the cross-scale crack evolution analysis method under strong earthquake is established and the coupled SBFEM-FEM analysis software is developed in the explicit earthquake wave motion input method frame. The dynamic failure analyses of slabs are performed for a 200-m-high CFRD considering the reinforcement ratio, vertical earthquake and water level of reservoir. The results indicate that the developed method can visually represent the seismic cracking evolution, conveniently locate weak areas of face slab, quantitatively determine the damage severity, and evaluate the aseismic measures. The research results may provide an effective method for the aseismic design and assessment of ultimate aseismic capacity of concrete slab. The proposed method can be extended to the failure analyses of other concrete structures and three-dimensional investigation and application easily.