Experimental investigation of wave reflection from sloped seawalls

In this study, the reflective behavior of sloped porous seawalls were investigated experimentally using physical modeling. Regular waves of wide range of heights and periods were used. Tests were carried out for a constant water depth of 0.27m and for different inclinations of seawall (i.e. θ = 45, 60, 75 and 90 ̊). It was found that the parameters of wave steepness, relative water depth, surf similarity parameter and the slope of seawall were influencing in predicting the reflection from the sloped porous seawall. The reflection coefficient (Kr) for sloped seawalls ranged from 0.36–0.77 and for the vertical porous seawall it was 0.59–0.83, whereas for the vertical plane wall, it was almost 1. The reduction in the wave reflection for the sloped seawalls as compared to the vertical porous seawall was about 28%. New empirical equations were developed for estimating the wave reflection coefficients from the proposed seawalls using nonlinear regression analysis. These found were calibrated using SPSS based on the experimental result. The results of this study will be useful in the design of energy dissipating type vertical quay walls in ports, sloped seawalls for shore protection from erosion and sloped caisson breakwaters.