不同护坡条件下波浪溢流海堤内坡水动力特征

Hydrodynamic characteristics analysis of wave overtopping on landside under different slope protection conditions

波浪溢流指强风暴潮引起堤前水位超过堤顶,海堤受到的越浪与溢流联合作用。波浪溢流一旦发生,极易引起大范围的海堤内坡侵蚀乃至溃堤,产生灾难性后果。基于1∶1的大型水槽试验,分析了波浪溢流过程中不同海堤内坡护坡条件下(碾压混凝土、铰接式护坡砖和高性能加筋草皮)海堤内坡水力学特征;建立了相应的内坡平均水深和平均流速计算模型,计算结果表明波浪溢流过程中海堤内坡上的波高分布仍符合瑞利分布,并分析了内坡上的特征波高和特征峰值水深之间的换算关系;提出了波浪溢流过程中海堤内坡上的均方根波高和波速经验计算式。

The wave overflow is a phenomenon that the water level caused by strong storm surge in front of the seawall exceeds the top of the seawall and the seawall is subjected to the combined action of the overtopping and overflow. It happens when the sea water level(SWL) is higher than the level crest under the impacts of the strong storm surge. With the presence of the combined wave and surge overtopping, it is very easy to cause large-scale erosion of the inner slope of the seawall and even break the seawall, resulting in catastrophic consequences. Based on the experimental results of the full-scale flume tests, the hydraulic characteristics of the flow along the landside slope of the seawall during combined wave and surge overtopping are tested and analyzed under different slope protection conditions, including roller compaction concrete, articulated concrete block and high-performance turf reinforcement mat. The empirical equations for average water depth and overflow velocities on the landside slope during the combined wave and surge overtopping are proposed under different slope protection conditions. It is found from the analysis results that the distribution of the wave height along the landside slope can be represented by the Rayleigh distribution, and the relationships between the characteristic wave heights and the characteristic peak water depths along the landside slope are established during the combined wave and surge overtopping. At the same time, the empirical equations for the root-mean-square wave height and wave velocities along the landside slope of the seawall during the combined wave and surge overtopping are also proposed in this paper. The research results can provide references for related researches on the landside slope protection under the combined wave and surge overtopping conditions.