Effects of Berms on Rubble Mound Breakwater Stability under Seismic Loading

For rubble mound breakwaters, incorporating a berm in the seaward slope can be very effective in reducing wave overtopping and mitigating wave loads acting on the breakwater armor elements. This research aims to investigate the effect of horizontal berm on the seismic response of conventional rubble mound breakwaters, considering various amplitudes and frequencies characterizing seismic loads. Finite element models of conventional rubble mound breakwaters, with and without berm, are developed using Plaxis 2D software for this purpose. Additionally, the stability of rubble mound breakwaters with berms is studied through various numerical models, considering different lengths and height levels of the berm. A comparative analysis of the results shows that rubble mound breakwaters incorporating berms exhibit lower deformation characteristics compared to those without berm. The numerical study results suggest that berms can significantly enhance the stability and reduce displacements of rubble mound breakwaters under seismic loading compared to breakwaters without berm. © 2024 The author(s).