Wave reflection from coastal structures

This paper analyses wave reflection for various type of structures, such as smooth and rock (permeable and impermeable core) slopes and slopes with all kind of artificial armour units. A database was prepared, based on existing databases for wave transmission and overtopping. A new formula was developed, whose shape fits all kind of straight slopes in design conditions by changing two calibration coefficients. Since reflection and overtopping performance are strongly related, it has been hypothesized and verified that these coefficients depend only on the roughness factor in the overtopping discharge formula. As the roughness factor is available for a wide variety of materials, the extension of the formula to different slopes is straightforward. A preliminary analysis on the effect of a low crest has been performed for rock permeable slopes only, showing that the developed formula can be applied also in this case with the introduction of a proper function of the relative crest height.