滑坡堰塞坝越顶溢流破坏的物理模型实验

滑坡堰塞坝作为结构松散的堆积物，随着上游水位的不断上涨，其稳定性不断降低，并存在突然溃坝的风险。以唐家山滑坡堰塞坝为研究对象，基于相似原理，开展符合坝体颗粒级配的室内水槽物理模型实验，模拟了不同坝后蓄水量、不同水位和不同颗粒物质组成条件下坝体渗流、漫顶破坏的整个过程。监测结果显示：堰塞坝漫顶溃坝主要分为渗流、漫顶、冲刷和溃决4个过程；坝体堆积颗粒级配越差，坝体允许渗流坡降越小；相同材料配比的坝体，上游水位相同时，坝体底部水平位移最大，且漫顶溃坝时溃口尺寸与蓄水量正相关。该研究结果揭示了堰塞坝漫顶破坏规律，可为堰塞坝溃坝防治提供理论参考。

Physical Model Experiment on Overtopping Overflow Failure of Landslide Dam

As a kind of loose structured deposits,the stability of landslide dams reduces with the upstream water level rising.Under the worst situation,a sudden dam-breaking would happen.Taking the Tangjianshan barrier dam as the research object,based on the similarity principle,the indoor flume model experiments were conducted to simulate the whole failure process in different conditions,including different impoundment,upstream water level,and particles composition.The monitoring results indicate that:The failure process can be mainly divided into seepage,overtopping,scour,and breach;The smaller the proportion of the composition particles accounts for,the lower the allowed seepage gradient of the dam is;Under the same grading of composed material and the same upstream water level,the sectional breach size is positively correlated with the impounding water.The experimental results reveal the overtopping failure law of landslide dams,and provide some theoretical reference for a breach prevention.