Connotation of deformation safety of high concrete face rockfill dams and its application

Based on the analysis of causes for serious damages of worldwide high concrete face rockfill dams (CFRDs), it is indicated that the empirical design concept of CFRDs should be discarded. The deformation safety is necessary besides the stability safety and seepage safety for high CFRDs. A new deformation coordination concept for high CFRDs comprising dam settlement coordination, dam displacement coordination, dam deformation in face slab normal direction and dam axis direction synchronously coordinating with face slab deformation is established. The connotation of deformation safety design of high CFRDs including deformation coordination standards, judgment criteria, calculation methods as well as counter measures, is put forward. The necessity of replacing the empirical design concept by the new deformation coordination concept is explained through the case study of Bakun Dam, 203.5 m in height.