关键词: 水利工程, 尾矿坝, 漫顶溃决, 溃坝流量, 泥沙浓度, 表面流速系数

Abstract: The high titanium slag, mountain sand and river sand were used as filling material for tailings dam. Experiment and theoretic analysis method were applied to investigate the difference of dam break process of tailings dam filled with three different materials with the same gradation under overtopping action. The research results show that the final breach width of tailings dam filled with high titanium slag is the smallest and the erosion rate of the dam body is the lowest. In the process of dam break, the material loss rate and downstream flood sediment concentration rate of tailings dam filled with mountain sand and river sand are higher than those filled with high titanium slag. The ratio of cross-section average velocity to surface velocity is defined as the surface velocity coefficient k, and the breach discharge is indirectly affected by the influence of sediment concentration and breach size on the k value. The theoretical derivation shows that there is a minimum k value when the sediment concentration is between 0.05 and 0.15, and the k value increases with the increase of the breach size.

Key words: hydraulic engineering, tailing dam, dam-break of overtopping, dam failure discharge, sand concentration, surface velocity coefficient