土石坝漫顶溃决及洪水演进研究进展

Review on overtopping failure and flood evolution of earth-rock dams

土石坝漫顶溃决往往在其下游产生巨大的洪水灾难,研究坝体溃决及洪水演进是防灾减灾的需要。对土石坝漫顶溃决过程现象、机理及其模拟的研究进展进行了综述。讨论了物理模型试验的尺度设计,总结了不同尺度、不同类型、不同条件溃坝试验的研究成果;按照参数模型、简化物理模型、精细物理模型,分类总结了漫顶溃坝数学模型研究进展;阐述了溃坝洪水演进方面的试验与模拟研究。在此基础上,对该研究领域今后的研究工作提出了若干展望,包括河道边界对溃坝过程及溃坝洪水传播过程的影响、非均质土石坝溃决机理、溃坝过程中挟沙水流冲蚀规律、溃坝下游河床的冲淤调整及泥沙分选、溃坝对水生态环境的冲击影响等。

Flood events caused by the overtopping failure of earth-rock dams often lead to catastrophic disasters.Therefore,examining the cause of the dam failure and studying the subsequent flood evolution processes are extremely important for disaster prevention and mitigation.This work reviewed the phenomena and mechanism of the overtopping failure of earth-rock dams and recent researches using physical experiments and numerical simulations.The scale design of physical model test is discussed,and the research findings of dam break experiments under different scales,dam types,and experimental conditions are summarized.Research progresses of numerical simulations of dam breaks using parametric models,simplified physically-based models,and detailed physically-based models are reviewed.Advances in numerical and experimental studies of the evolution of flood caused by dam failure are highlighted.After reviewing the literature,some future research directions are proposed.They include examining the influence of river boundary conditions on dam failure and the subsequent flood propagation processes,reconciling the mechanism of the failure of heterogeneous earth-rock dams,investigating the erosion law of sediment-laden flow during dam breaks,studying the downstream scouring and silting and riverbed sediment sorting after dam failure,and evaluating the impact of dam failure on the aquatic ecosystems.