Reliability Theory as a Tool in Offshore Structural Design and Construction

Offshore structures are subject to poorly defined hazards such as storms, continued wave action, corrosion and ship impact, and are themselves not well defined in terms of their strength or resistance. Traditional design methods for offshore structures have, on the whole, worked well, but there are now moves to develop probabilistically-based design rules. This is a sound strategy since uncertainties in information can be rationally incorporated in the design and analysis process. The application of reliability theory extends, however, also to the sphere of analysis and decision making in the construction stages. The paper briefly reviews the essential concepts of structural reliability theory and then indicates the various ways in which it has been or can be applied in practical situations. This includes analysis for peak loading and for fatigue as well as other criteria. Some ongoing research areas will be noted.