考虑精细地形的尾矿库溃坝外泄泥流运移规律研究

Research on migration law of tailings dam breach runout mud flow considering fine terrains

为更科学地开展尾矿库风险评价,提升库区下游防减灾能力,首先引入光滑粒子流体动力学(SPH)方法,使用无人机(UAV)遥感技术获取的高分辨率地形数据,研究尾矿库溃坝外泄泥流在下游精细地形上的运移规律;然后以华东某尾矿库为研究案例,分析泥流流动状态及关键指标。结果表明:案例中,溃坝发生15 s内,泥流覆盖坝脚处,以超12 m/s流速向沟谷内流动,受沟谷地形影响,流速峰值升至15 m/s以上;该尾矿库溃坝模拟结果受地形因素主导,大量高速流动泥流迅速聚集在沟谷,且影响扩散范围较广;流速、冲击力及淹没深度指标分析显示,下游苗圃、厂房面临较高风险。通过UAV遥感技术可获取库区及周边精细地形图片,具备分辨率高、时效性强、自动化程度高等优势。考虑精细地形的SPH溃坝模拟方法具备可行性与推广价值。

In order to carry out the risk assessment of tailings pond more scientifically and further improve the ability of disaster prevention and reduction,the migration law of tailings dam breach runout mud flow on downstream fine terrains was studied.The meshless Smooth Particle Hydrodynamics(SPH)method was introduced.UAV remote sensing technology was used to obtain high-resolution terrains.A case study of a certain tailings pond in East China was carried out.The flow state and key indicators of the runout mud flow were analyzed.The results show that:the dam toe is submerged in 15 s after the dam breach.The flow rushes to the downstream valley with a high velocity of over 12 m/s.The peak velocity reaches 15 m/s due to the influence of valley topography.The modelling results are dominated by downstream terrains.The tailings mud flow gathers quickly through the downstream valley at a high velocity.Eventually a significant impact range is observed.The indicators of flow velocity,impact force and submerged depth indicate that the downstream seedling nursery and factory plant are exposed to high risks of potential dam breach.UAV remote sensing technology can realize the fine terrains data acquisition of tailings pond and its downstream area,with the advantages of high resolution,great timeliness and automation.The proposed tailings dam breach SPH modelling method considering fine terrains is then proved feasible and can be further popularized.