头顶尾矿库溃坝下游平原区防护措施优选研究

头顶尾矿库安全风险巨大，极易引发重大安全事故，因此，对该类尾矿库溃坝泥石流演进过程和下游防护措施进行研究具有重要意义。针对下游为开阔平原地形的尾矿库，通过模型试验与数值模拟两种方 法，研究了在不同下游拦挡坝布置形式下，坝体下游各位置的泥沙淤积厚度以及淹没范围，在此基础上对下游防护拦挡坝的布置形式进行了优选。通过分析溃坝后下游泥沙淤积厚度以及淹没范围，得出：①拦挡坝具 有拦挡和导流的双重作用，其中导流又分为横向导流和纵向导流。②坝体角度不同，拦挡坝发挥的作用不同：坝体夹角越大，表现为拦挡作用越明显；坝体夹角越小，表现为导流作用越明显。③坝体夹角为128°的拦 挡坝为最优防护措施，原因在于该坝型的折角可减缓下泄泥沙对坝体的冲击力，并且该坝型的双向导流作用增大了下泄泥沙的流动范围，降低了下游泥沙淤积厚度，能够使泥沙有效地排到周围，减小对下游居民的危 害。研究成果可为下游尾矿库防护措施优选提供决策依据。

Study on the Optimization of Protective Measures in Plain Area Downstream of Dam Break of Overhead Tailings Pond

The safety risk of overhead tailings pond is huge,and it is easy to cause major safety accidents. Therefore,it is of great significance to study the evolution process and downstream protection measures of debris flow in overhead tailings pond. Aiming at the tailing pond with open plain terrain in the downstream,through two methods of model test and numerical simulation,the sediment deposition thickness and inundation range of each position in the downstream of the dam body under different layout forms of the downstream retaining dam are studied. On this basis,the layout forms of the downstream protective retaining dam are optimized. Based on the analysis of the downstream sediment deposition thickness and inundation range after dam break,it can be concluded that:(1) the retaining dam has the dual function of retaining and diversion,and the diversion is divided into transverse diversion and longitudinal diversion.(2) the function of the retaining dam is different with different dam body angles: the larger the angle between the dam body is,the more obvious the retaining function is;the smaller the angle between the dam body is,the more obvious the diversion function is.(3) The retaining dam with an included angle of128° is the best protective measure,because the angle of the dam type can slow down the impact force of the discharged sediment on the dam body,and the two-way diversion of the dam type increases the flow range of the discharged sediment,reduces the thickness of the downstream sediment deposition,enables the sediment to be effectively discharged around,and reduces the harm to the downstream residents. The research results can provide decision-making basis for the optimization of downstream protective measures of tailings pond.