THEORETICAL SOLUTION FOR SEEPAGE FLOW IN OVERTOPPED ROCKFILL

Non-Darcy flow conditions can develop for flow over a rockfill dam wit h a wide profile (e.g., a high rockfill dam under construction in a fl ood period), flow in gravel river reaches, and overland flow. Non-Darc y Bow can also occur in nonconventional rockfill spillways. Such condi tions are due to seepage flow with a high Reynolds number in rockfill (or gravel) and the interaction between the overtopping flow and the s eepage flow. In this paper, theoretical solutions for the turbulent se epage flow at the transition zone (that is, the seepage zone between t he overtopping zone and the pressure seepage zone) are presented. The Prandtl mixing-length turbulent theory is used with the non-Darcy seep age law to solve the problem. Analytical results are compared with pub lished experimental data.