不同填筑材料对尾矿坝漫顶溃决过程影响试验研究

Experiment Study on Effect of Different Filling Material onDam-Break of Overtopping of Tailings Dam

选取高钛渣、山沙及河沙作为尾矿坝填筑材料,采用试验与理论分析方法研究了相同级配下的3种不同材料填筑尾矿坝在洪水漫顶作用下溃坝过程差异。研究结果表明:高钛渣填筑尾矿坝溃坝后最终溃口宽度最小,坝体侵蚀率最低。山沙和河沙填筑尾矿坝溃坝过程溃口材料损失率和下游洪水含沙率高于高钛渣填筑尾矿坝。将断面平均流速与水流表面流速比值定义为表面流速系数k,泥沙浓度和溃口尺度通过影响k值间接影响溃口流量。理论推导表明当泥沙浓度介于0.05~0.15时存在一个最小k值,当溃口尺寸增大时,k值随之增大。

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.