基于模型相似理论的尾矿库溃坝试验研究

Experimental Study on Tailings Dam Break Based on Model Similarity Theory

为确定尾矿库溃坝灾害后果及影响范围,提高库区下游防灾减灾及应急管理水平,应用模型相似理论对某尾矿库进行了室外溃坝试验,探究了发生溃坝事故时泥石流的流速变化、冲击高度和沉积深度等流动特性,并预测了下游溃坝影响范围。试验结果表明,流速随流动距离逐渐降低,地面粗糙度对流速影响较大,有土工布时的流速是无土工布时的1.1～1.3倍;下游5个断面位置的冲击高度为12～20m,沉积深度为6～14m;在靠近溃坝口处的冲击高度最大,但沉积深度最小,随矿浆泥石流的运动,冲击高度随地形高差交替变化;该尾矿库下游36户居民点中,位于溃坝影响范围红线内的有6户,该红线的范围与溃决的矿浆量、下游高差、沟谷底宽、两岸坡度和高程等因素有关。研究方法和结果可作为确定下游搬迁点或制定应急管理对策的重要依据。

In order to determine the consequences and impact scope of tailings dam break,and improve the disaster prevention,reduction,and emergency management in the downstream,an outdoor dam break test of a tailings dam was carried out by analogous model theory.The flow characteristics of mudslide flow velocity,impact height and deposition depth during the dam break were explored.And the influencing scope of downstream dam break was predicted.The test results showed that the flow velocity decreased gradually with the increase of flow distance,and the roughness of the ground had a great influence on the flow velocity.The flow velocity with geotextile was 1.1~1.3times of that without geotextile.The impact height of the five downstream sections was 12~20mand the deposition depth was 6~14m.The impact height was the largest near the dam break,but the deposition depth was the minimal.With the movement of slurry and mudslide,the impact height changed alternately with the terrain height difference.Among the 36households in the downstream of the tailings dam,6households located in the red line of the dam break area.The scope of the red line was related to factors such as the amount of slurry,the downstream height difference,the width of the valley bottom,the slope and elevation of both sides,and so on.The research methods and results could be used as an important basis for determining downstream relocation points or formulating emergency management countermeasures.