A Comparison of XblocPlus and Rock Armour on Sustainability, Costs and Climate Resilience

In this paper rock armour and XblocPlus are compared with regard to costs, carbon emissions and the expected maintenance need. A simplified method is presented to predict damage development during a structure lifetime using a Monte Carlo analysis. This MC analysis is based on a limited number of extreme wave conditions with return periods between 1 year and 1,000 years. Two case studies are presented for which the authors received a design with rock armour and prepared an alternative design with XblocPlus. The maintenance need of the case studies is predicted for two wave climates: 1) the wave climate for 2015 which is seen as current day wave climate and 2) the wave climate that is predicted for the year 2115. The rock armoured structures have a high probability to need maintenance during their 50 years lifetime and increasing wave heights due to climate change increase this probability. The XblocPlus structures have a low probability to need maintenance and a high resilience against increasing waves due to climate change. For the two case studies the XblocPlus structures perform better than the rock armoured structures with regard to cost and carbon emissions.