Influence of Abutment Slope Angle Variety on the Deformation and Stress of the Concrete-Faced Rockfill Dam During Initial Impoundment

Favorable valley terrain for building dams is gradually decreasing. The primary objective of this study is to investigate the influence of abutment slope angle variety on the deformation and stress of concrete-faced rockfill dam (CFRD). First, the effect of abutment slope angle on perimeter joint deformation is investigated using CFRD monitoring data in China. A normalized deformation index (CDS) is proposed to evaluate the relationship between perimeter joint deformation and the steepest abutment slope angle. Results indicate that perimeter joint deformation increases nonlinearly with the steepest abutment slope angle. Then, numerical analysis is conducted on Miaojiaba CFRD under three types of abutment slope variety from upstream to downstream. We focus on the effect of abutment slope angle variety from upstream to downstream on CFRD behavior. In the analysis, the terrain shape line is assumed to be constant at the downstream slope foot, and the abutment slope angle increases linearly from upstream to downstream. The Duncan–Chang E–B model is used in nonlinear analysis for rockfill, and the slab–rockfill interfaces are modeled using contact elements with Coulomb friction. An influence sphere is proposed for the different types of abutment slope angles. Results indicate that face slab deformation is more dependent on abutment slope angle than rockfill deformation.