Seepage–Creep Coupling Analysis of Concrete-Face Rockfill Dam Built on Alluvium Foundation

The foundation and dam body below the seepage-free surface are in a saturated seepage state for a concrete-face rockfill dam (CFRD) built on a deep alluvium foundation. The seepage and stress coupling effect could influence the dam deformation behavior. This study focuses on the seepage–creep coupling behavior of the CFRD on alluvium. The Drucker–Prager (D–P) plastic and time-hardening creep models are used to describe the instantaneous and creep deformations of rockfill and alluvium materials. The back propagation (BP) neural network method is adopted to invert the material creep model parameters. The dam and foundation seepage process is described using Signorini’s type variational inequality method. A seepage–creep coupling analysis method for CFRDs on alluvium is proposed on the basis of the momentum conservation principle and the Kozeny–Carman equation. The deformation mechanism and evolution process of CFRD on alluvium are investigated whilst considering the seepage–creep coupling effect. The influence of the seepage effect on the dam’ long-term deformation is discussed.