基于FLUENT的狭长型水库滑坡涌浪研究

Study on landslide surge of narrow reservoir based on FLUENT model

滑坡涌浪是水库库区岸坡岩土体失稳下滑冲击库区水体而产生波浪的现象。大规模的滑坡可使库区产生巨大的涌浪,传播至坝前甚至会翻越大坝造成坝体溃决,严重威胁下游城市居民生命财产安全。以长岭皮水库为例,采用FLUENT软件模拟其库尾渣土填埋场发生不同规模滑坡所激起的坝址处最大浪高,并与潘家铮方法、中国水科院经验公式法和美国土木工程协会推荐方法等经验公式的计算结果对比;分析了滑坡体入水横断面形态及入水角度对滑坡涌浪高度的影响,发现涌浪最大浪高与滑坡体入水临水面面积呈线性正相关,并与入水角度呈非线性先负相关后正相关;提出了滑坡涌浪不漫顶的滑坡体临界体积。不同滑坡工况下的计算结果可为长岭皮水库库尾滑坡涌浪灾害预防提供参考。

Landslide surge is caused by the loss of stability of the slope rock and soil in reservoirs.The water waves generated by landslides can propagate to the dam,or even break the dam,threatening the life and property safety of the downstream.Taking the Changlingpi reservoir for example,based on FLUENT,this paper simulates the maximum wave height of the dam site aroused by different scale landslide in the Changpingpi reservoir tail where residue soil piles up,and compares it with the Pan Jiazheng’s method,the empirical formula by China Academy of Water Resources and Hydropower Sciences,and the recommended method of American Civil Engineering Association.The influence of the cross-sectional morphology of landslide body and the angle of entering water of landslide on the height of landslide surge were analyzed.The maximum wave height is correlated with the area of the bottom side of the landslide body which faces the water and is nonlinear related to the angle of entering water of landslide,the maximum wave is first negative correlated to the angle and then positive correlated with the angle.The critical volume of landslide in which case the surge can’t surmount the dam is proposed.Calculation results under different landslide conditions can provide a basis for landslide surge prevention in the reservoir tail of Changlingpi.