规则波作用下珊瑚礁直立式护岸波浪力大比尺模型实验研究

Experimental study of regular wave force on vertical seawall on reefs in the large wave flume

基于大比尺波浪水槽试验,采用弗劳德相似准则,按照1:15的模型比尺,开展了规则波作用下珊瑚礁地形上的波浪和直立式护岸的相互作用的研究,在不同水深和波浪条件下,测量了直立式护岸所受压强,并与规范值进行对比。实验结果表明实验测量值明显大于规范计算值;直立式护岸所受压强值与入射波波高和礁坪水深正相关,随护岸距礁缘距离增大而减小。通过将时均水深、增水、护岸距礁缘的距离无量纲化跟无量纲压强进行分析,得出结果表明当礁坪上水深足够深、护岸距礁缘距离小于0.5倍的波长的时候,所受压强只和入射波高有关;而波浪在礁坪上的增水越高,直立式护岸所受到的压强越大。因此综合考虑了周期、礁坪水深、增水和距离,拟合出基于该实验中筑堤珊瑚礁地形的直立式护岸波浪力估算公式,拟合公式计算精度高于现有规范公式。

Based on Froud similarity criterion,experimental study with 1:15 scale of regular wave force on vertical seawall on reefs was conducted in the large wave flume of Tianjin Research Institute for Water Transport Engineering.Under different water depths and wave conditions,the pressure on the vertical seawall was measured and compared with the standard value.The experimental results show that the measurement value is obviously greater than the standard calculation value.The pressure of the vertical seawall is directly proportional to the incident wave height and reef flat water depth,and inversely proportional to the distance between the seawall the reef edge.By analyzing the relationship among dimensionless time average water depth,dimensionless water increase,dimensionless distance and dimensionless pressure,the results show that when the water depth on the reef flat is deep enough and the distance between the seawall and the edge of the reef is less than 0.5 times of the wavelength,the pressure is only related to the height of the incident wave;and the more the setup on the reef flat,the greater the pressure on the vertical seawall.Therefore,considering the period,reef flat water depth,setup and distance,a comprehensive wave force estimation formula for vertical seawall which is suitable for coral reef terrain is fitted.The calculation accuracy of the fitting formula is higher than the standard formula.