Desk Study Tools for Upgrade of Breakwaters against Increased Loadings Caused by Climate Change

Burcharth et al. (2014) studied different upgrade solutions for a typical shallow water revetment and found that the most economical solution was to add an extra layer of armour rocks tothe existing two layers. Because none of the existing design formulae for armour stability and overtopping cover designs with armour consisting of three layer of rocks, the related design parameters had to be estimated. R ecently performed physical model tests presented in Eldrup et al. (2019) provide information of the performance of three layer rock armour and formed the basis for determination of the related notional permeability factor in the Van der Meer (1988) rock armour stability formula. The application of this formula and the Eldrup and Lykke Andersen (2018) overtopping formula is discussed in relation to armour consisting of two and three layers of rocks. The study shows that upgrading from two to three rock armour is a method to increase the stability and reduce the wave overtopping of existing structures.