Experimental study on scour occurring at a vertical impermeable submerged breakwater

In recent years, local scour has been brought to attention because it may have a negative effect on coastal structures. This paper describes an experimental investigation of local scour in front of an impermeable submerged breakwater with a vertical offshore face. Experimental results show that the scour pattern in front of the submerged breakwater is similar to that in front of a vertical-wall breakwater, although there is a slight difference in the locations of the scour and the deposition.

The maximum scour depth normalized by the incident wave height is found to decrease exponentially with relative water depth (the ratio of the water depth to wavelength of the incident wave height). Also, the scour depth is dependent on the reflection coefficient of the submerged breakwater. A new estimation method for evaluating scour depth is developed and provides excellent correlation with all experimental data available in the literature.