Estimating design wave for offshore structures in Italian waters

This paper describes a methodology for estimating the design wave parameters for offshore structures. For the estimation of the design wave height the concept of an equivalent triangular storm (ETS) is discussed. It is shown how it overcomes the limitations of previous methodologies. The simplicity of the estimation of the design wave period by means of the quasi-determinism theory has been demonstraded. It only requires the knowledge of the significant wave height of the sea state in which the highest wave of given design return period will occur with the highest probability. The theory can be applied because the design wave height is an exceptionally high wave for its sea state Final discussion address examples of the estimation of design wave data to determine the size of offshore structures to be built along the coasts of Italy, the Pacific and Atlantic Oceans and Gulf of Alaska, using wave data gathered from instruments managed by the Environment and Territory Agency and the National Buoy Centre.