极端条件下尾矿库排洪系统失效溃坝影响规律研究

Study on the law of dam failure in tailings pond drainage system under extreme conditions

为了有效减少尾矿库溃坝对周围各类设施带来的不良作用,采用MIKE 21平面二维水动力模块模拟最终堆积标高时达到漫顶情况下出现溃口且溃口逐渐扩大导致失稳对周围1 km各类设施的影响规律,溃口形状为倒梯形,溃口位置选取对下游最不利位置(尾矿库东北坝),生成二维溃坝演进模型,分别得到溃坝范围内的流量过程、淹没高程、淹没范围等数据。研究表明:该尾矿库在正常标高且良好管理下运行时,不会发生溃坝;当水库达到最高洪水位、排洪系统全部失效、遭遇远超1000年一遇洪水、24 h入库洪水总量超出安全运行水位至坝顶之间库容时,可能产生漫顶溃坝风险;洪水漫顶溃坝和边坡局部失稳溃坝后下泄的尾矿砂对东北侧砂场的影响均大于东南侧;洪水漫顶溃坝影响范围未超过1 km;局部边坡失稳溃坝下东北侧的溃坝影响范围超过1 km,但此时溃坝已停止,泥石流不再向前移动,风险处于可控状态。

In order to effectively reduce the adverse effects of tailings pond dam break on various surrounding facilities,the MIKE 21 plane two-dimensional hydrodynamic module is used to simulate the influence law of instability on various facilities around 1km when the final stacking elevation reaches the overtop and the collapse gradually expands,and the collapse shape is inverted trapezoid.The most disadvantageous location downstream(northeast dam of tailings pond)was selected to generate a two-dimensional dam break evolution model,and data such as flow process,inundation elevation and inundation range within the dam break range were obtained respectively.The research shows that the dam break will not occur when the tailings pond runs under normal eleva-tion and good management.When the reservoir reaches the maximum flood level,the flood drainage system fails,the flood is far more than once in 1000 years,and the total amount of flood in 24 h exceeds the storage capacity between the safe operating level and the crest of the dam,there may be the risk of overtopping and dam break.The impact of tailing sand on the northeast sand field is greater than that on the southeast sand field.The impact area of flood overtopping dam failure is less than 1 km;The influence range of the dam failure on the northeast side of the local slope failure is more than 1km,but the dam failure has stopped at this time,the debris flow no longer moves forward,and the risk is under control.