Three-dimensional refined analysis of seismic cracking and anti-seismic measures performance of concrete face slab in CFRDs

The concrete face slab is the primary anti-seepage component of concrete faced rockfill dams (CFRDs). Therefore, the seismic safety of the slab is an important issue. In this paper, the cohesive zone model and the explicit solution are expanded to conduct 3D seismic failure analysis of a CFRD. A combination of the generalized plasticity model of rockfill, state-dependent elasto-plastic model of soil-structure interfaces, a non-uniform wave input method and the scaled boundary finite element method is used to perform an elasto-plastic, cross-scale analysis of the seismic cracking evolution of concrete face slabs. The above combined method is used to investigate the cracking mechanism, cracking characteristics and potential anti-seismic measures. The results indicate that the cyclic deformation caused by the earthquake results in the formation of horizontal, connected cracks in the middle of the slab at 70-75% of the dam height. In addition, the plastic deformation of the rockfill leads to the formation of horizontal, unconnected cracks on both sides of the slab at 85% of the dam height. A comprehensive anti-seismic measure is proposed based on material property improvement and structural optimization, decreasing the maximum crack width and the total crack length by 21% and 89.9%, respectively.