均质土坝漫顶溃坝模型相似准则研究

由于土石坝溃坝过程具有强非线性,溃坝机理非常复杂,土石坝溃坝模型试验相似理论研究有较大的难度。基于近年来南京水利科学研究院开展的5次国内外最高黏性土均质坝漫顶溃坝实体试验及20多组室内漫顶溃坝试验,"陡坎"式侵蚀被认为是土石坝漫顶溃坝的重要机理之一。从这一机理出发,该文推导获得了均质土坝漫顶溃坝过程模型试验的两个重要相似准则:"陡坎"移动速度相似比尺λR及溃口流量过程时间比尺λt。两次现场大尺度溃坝试验数据验证表明,该文获得的溃坝模型相似率能够较好的反演均质土坝漫顶溃坝过程,有较好的参考价值。

Similarity criteria of homogeneous embankment failure due to overtopping flow

Since the process of dam breach is a strongly nonlinear and very complex, one has difficulty to decide similarity criteria of dam breach in practical engineerings. According to five prototype tests of homogeneous embankment failure in the world and twenty laboratory tests completed by Nanjing Hydraulic Research Institute, the mechanism of homogeneous embankment failure due to overtopping flow was obtained ,and it was call as "head-cut". Based on this mechanism and results from above tests, head-cut migration rate similarity scale λ_R and the time of flow process similarity scale λ_t of homogeneous embankment failure due to overtopping flow were derived. Based on the similarity criteria, several experiments were conducted in the two field tests. The results verified the similarity criteria is available, and it could be used to simulate the dam breach process for homogeneous embankment failure due to overtopping flow.