Wave-loads fragility analysis of jetty structures

The risk assessment of maritime structures directly exposed to and interacting with the incoming wave field requires a careful description of the wave induced loads (wave-loads), and the assessment of the fragility of the structure subject to these loads (wave-load fragility). In this paper, a procedure for the wave-load fragility assessment of a specific type of maritime structure, the exposed jetties, is illustrated. A jetty is a structure projecting from the shore and providing berths to vessels in relatively deep water. For these structures, wave-loads depends on both the kinematics of the incoming wave and the characteristics of the structure; more specifically, in some cases, in addition to the loads acting on the supporting elements, also wave-in-deck loads, acting on the deck, are to be considered. Starting from the original work by Morison, sophisticated models of wave-in-deck loads have been developed in recent years. An up-to-date model of the wave-in-deck loads is described and applied to the fragility assessment of an example structure. The proposed procedure has been found to be able to take into account the various sources of uncertainty with a limited amount of computational time.