Abstract: The upstream damming is adopted in the Yangjiawan tailings reservoir， but the slime interlayer has seriously hindered the vertical infiltration of water. The length of the accumulative dam is increased with the sub-dam uplifting of the tailings reservoir， which is beyond the drainage range of the horizontal filter tube in the original radial discharge well. In addition， due to the hinder by the two-side base rock， the seepage path becomes longer， resulting that the local saturation line of the tailing dam is rather high， partial swamps appear at the outer slope of the sub-dam， and seepage occurs at the cut-off ditch on both sides of dam abutment. Therefore， the drainage and reinforcement of Yangjiwan tailings reservoir are required. The combined infiltration process of the multi-layer horizontal filter tube at the radial discharge well and the horizontal filter tube at the dam surface is adopted to improve the drainage capacity， reduce the infiltration line of the dam body， and increase the buried depth of the infiltrating line by an average of 0.67 m. It comes true that the actual infiltration line is not higher than the design of the control infiltration line to ensure the safety operation of the tailings dam.

Key words: Tailings dump, Infiltration line, Seepage path, Radial discharge well, Horizontal filter drainage