模型试验及数值模拟下尾矿库溃坝尾砂流演变预测

尾矿库溃坝所产生的尾砂流类似于地质灾害中的泥石流,具有发展迅速、破坏性强、影响范围广和预警时间不足等特点,研究溃坝尾砂流的演变规律及其影响范围对防灾减灾具有重要的意义。该研究利用RAMMS碎屑流软件建立了数值三维模型进行数值仿真溃坝模拟,通过物理模型(1∶150)试验研究了溃坝的尾砂流对下游的演变进程和影响范围,并将其试验数据与数值计算结果对比分析,验证了数值模拟在溃坝仿真上的可靠性和有效性。结果表明:以漫顶水流到达拦砂坝底开始计时,尾矿坝溃坝9 min尾砂流开始冲击距尾矿坝0.7 km处的下游村庄;随着溃坝的持续,溃坝泥砂淤积逐步加深,水位继续升高,并在18 min对下游造成全面淹没,影响范围达0.558 km ²,库内尾砂的溃泄总量可达1.3×10⁷ m ³。建议在尾矿库的设计、管理和风险评估过程中,结合潜在的危险范围,合理的增加防灾减灾的措施。

Evolution prediction of tailings flow in dam break of tailings pond under model test and numerical simulation

The Tailings flow generated by dam break of tailings pond is similar to debris flow in geological disasters.It has characteristics of rapid development,strong destructiveness,wide influence range and insufficient early warning time.Studying its evolution law and influence range is of great significance for disaster prevention and mitigation.Here,a numerical 3D model was established by using RAMMS debris flow software for numerical simulation.The downstream evolution process and influence range of tailings flow due to dam break were studied through a physical model(1∶150)tests.The test data were compared with the numerical calculation ones to verify the reliability and effectiveness of numerical simulation in dam break simulation.The results showed that timing starts when the overtopping flow reaches the bottom of the sand retaining dam,after tailings dam breaks for 9 minutes,tailings flow begins to impact downstream villages of 0.7 km away from tailings dam;with dam’s continuously breaking,sediment deposition of dam break is gradually deepened,water level continues to rise,and downstream is completely submerged within 18 minutes,the influence range reaches 0.558 km ²,and the total amount of tailings escaped from pond can reach 1.3×10⁷ m ³;during design,management and risk assessment of tailings pond,combined with the potential risk range,reasonable measures for disaster prevention and mitigation should be added.