中线式尾矿库洪水漫顶溃坝演化规律模拟研究

为了解中线式尾矿库洪水漫顶溃坝的过程和机理，并提出可行的工程措施，以某中线式尾矿库及下游周边环境为研究对象，采用物理模型试验和数值模拟法对中线式与上游式尾矿库安全性进行对比研究。研究结果表明:由于中线式尾矿库外坝坡堆积粗尾砂的渗透系数偏大，其较上游式尾矿库溃口发展的速率更快，溃坝过程持续时间约14.5 h，坝顶被泄流冲刷形成的溃口宽约289 m，尾矿库下游沟道研究范围内尾矿淤积约871万m3，大量的尾矿仍滞留在库内；采用数值模拟得出的演化趋势与物理模型试验基本一致，但数值模拟计算的尾砂流动速度较快；在拦砂坝下游修建应急拦砂坝工程，物理模型试验表明拦滞尾矿洪水时间约38 min，数值模拟结果表明拦滞尾矿洪水时间约16 min，因此应急拦砂坝措施可有效延长应急逃生时间，减轻溃坝对下游居民的影响。

Simulation research on evolution law of flood overtopping dam break of mid-line tailings pond

In order to understand the process and mechanism of flood overtopping dam break of the mid-line tailings pond,and propose the feasible engineering measures,taking a mid-line tailings pond and its downstream surrounding environment as the research object,the comparative research on safety of mid-line and upstream tailings pond was conducted by using the physical model tests and numerical simulation method.The results showed that because the permeability coefficient of the coarse tailings accumulated on the outer dam slope of the mid-line tailings pond was relatively large,its development rate of tailings pond breach was faster than that of the upstream method.The dam break process lasted about 14.5 hours,and the width of breach on dam top being scoured by the discharge was about 289 m,and the tailings siltation in the research area of downstream channel of the tailing pond was about 8.71 million m3,but a large amount of tailings were still trapped in the pond.The evolution trend obtained by numerical simulation was basically the same as the physical model test,but the tailings flow rate calculated by numerical simulation was faster.When an emergency sand-retaining dam project was built at downstream of the sand-retaining dam,the physical model test showed that the blocking time of tailings flood was about 38 minutes,while the numerical simulation results showed that the blocking time of tailings flood was about 16 minutes.Therefore,the measure of emergency sand-retaining dam can effectively extend the emergency escape time and reduce the impact of dam break on the downstream residents.