“5·12”汶川地震诱发了大量山体滑坡,导致山区沟道内形成大量松散堵塞坝,其在山洪作用下可能发生溃决,而上游来流及堵塞坝形态对堵塞坝的溃决模式具有重要影响。通过水槽实验研究了不同上游来流条件及堵塞坝形态条件下堵塞坝的溃决过程,将堵塞坝的溃决模式概括为4种:正常溢流、洪水过坝冲刷、无爬高侧蚀以及爬高和侧蚀。研究了不同溃决模式下,堵塞坝的坝体溃决过程和机理,分析了不同溃决模式下溃口流量、溃决历时及溃口发展规律之间的差异。在前人研究成果的基础上,分析了正常溢流模式和无爬高侧蚀模式的溃口发展数值计算模型,借助于Meyer-Peter与Müller泥沙输移公式,计算了洪水过坝冲刷模式下,坝体溃决过程中单宽冲刷率的变化规律,并与实测值比较吻合良好。由于水流与堵塞坝相互作用的复杂性,目前对单个堵塞坝的溃决机制及沟道内多个堵塞坝级联溃决机制等问题的研究仍然不够深入,需要开展大量的研究工作。 A large number of landslides were induced in the May 12 Wenchuan earthquake, which led to the formation of a large number of loose clogging dams in the mountainous channel, which could be ruptured under the action of flash floods. However, upstream inflow and plugging dams shapes are important for the dam collapse model influences. Through the experiment of the sink, the different upstream flow conditions and the failure process of plugging dam under the condition of plugging dam were studied. The failure modes of plugging dam were summarized as four types: normal overflow, flood dam erosion, And side eclipse. The failure process and mechanism of block dam of dam blockage in different collapse modes are studied. The differences of burst flow, ultralow duration and ulcer development in different collapse modes are analyzed. Based on the research results of predecessors, the numerical model for the development of the breach in the normal overflow mode and the non-creeping lateral erosion mode is analyzed. With the help of the Meyer-Peter and Müller sediment transport equations, , The change rule of single-wide flushing rate in the process of dam collapsing, and is in good agreement with the measured value. Due to the complexity of the interaction between the water flow and the plugging dam, the research on the failure mechanism of single plugging dam and the multiple cascade dam collapse mechanisms in the channel are still not deep enough, and a great deal of research work is needed.