Rock stability of rubble mound breakwaters with a berm

van Gent, M. R. (2013). Rock stability of rubble mound breakwaters with a berm. Coastal Engineering, 78, 35-45.

 

Breakwaters with a berm can significantly reduce overtopping and reduce the required rock size compared to straight slopes without a berm. Here, the stability of rock slopes with a horizontal berm has been studied by means of physical model tests to provide information on the required rock size. The tests and analysis are focussed on the slope above the berm as well as the slope below the berm. Also the stability of the rock at the berm is addressed. The influence of the slope angle (1:2 and 1:4), the width of the berm, the level of the berm, and the wave steepness has been investigated. Based on the test results prediction formulae have been derived to quantify the required rock size for rubble mound breakwaters with a berm. Especially for the slope above the berm, the rock size can be reduced significantly compared to straight slopes.