Numerical simulation of seepage field in the tailing dam with draining seepage system

Numerical seepage model of tailing dam based on finite-element method is established. By constructing special grid system and intermediate boundary conditions, combined drain seepage system (horizontal drain pipe + transverse- longitudinal blind drainage ditch) is well achieved in the model and the results of model analysis are verified by the results of experiments. Through the numerical simulation of the seepage in the tailing pond, seepage velocity field and seepage surface and water head distribution in both the transverse and longitudinal directions in different filling period and different drain seepage conditions have given. Analysis shows that water head change in slag accumulative area is relatively small and the local seepage slope is big in the dam-toe in the initial stage. As the increase of the filling height, the seepage slope increases correspondingly. The changing of the seepage field in three drain-seepage conditions is analyzed. After setting the combined drain seepage system, the seepage face is basically distributed along the drainage pipe. The seepage slope reduces obviously and meets requirements of the dam stability.