Wave loading, overtopping and transmission of low crest caisson breakwaters

Recent LNG projects have pointed out the efficiency of low crested caissons breakwaters in providing shelter from waves to LNG terminals during frequent conditions whilst allowing for wave overtopping / transmission during most severe storms, reducing the design loads and therefore the overall cost of the breakwater. Unfortunately, little is known on hydrodynamic behaviour and loading of low crested structures heavily overtopped by long waves and use of existing design codes generally leads to over-design and excessive construction costs. Bearing this in mind, both physical and numerical models have been successfully applied to investigate wave-structure interaction problems and in particular to improve accuracy and increase confidence in the estimations of wave loading, wave overtopping and transmission over low crested structures. Tentative semi-empirical formulas are presented for wave overtopping and wave transmission based on new experimental data.