Key issues on seepage flow analysis in large scale hydropower projects

Seepage control is one of the key technical issues in large-scale hydropower engineering practices, and seepage flow analysis is indispensable to the optimization design of seepage control systems. In this study, the physical mechanisms associated with various engineering measures for seepage control are investigated and categorized into four types, i.e., control by coupled processes, control by initial states, control by hydraulic properties and control by boundary conditions. The effectiveness and advantages of the variational inequality approach of Signorini’s type for steady/non-steady seepage flow are presented. Also demonstrated are the SVA method for numerical modeling of drainage holes, the back analysis of initial seepage field, and the strongly coupled hydromechanical mechanism in fractured rocks and its numerical modeling. The research results may be helpful for the seepage flow analysis and the optimization design of seepage control systems in large scale hydropower projects.