Structural reliability theory in the wider safety context

This paper considers the role of structural reliability theory in the wider context of (i) achieving structural safety in practice and (ii) as part of safety assessment for engineering and other projects more generally, including its relationship to achievement of adequate safety in the community generally. It notes that the rules for the design of structures have advanced from 'Factor of Safety' to more rational procedures and these now include the widespread use of structural reliability theory for calibrating design codes. While this is an admirable achievement from a structural engineering viewpoint, and can be considered as a 'stand-alone' matter, increasingly there is an expectation that safety matters in structural engineering must be seen also in a wider perspective, that is in the context of societal expectations for structural engineering. As a result there remain a number of issues for clarification, including how the structural probability measures relate to observations about failures of actual structures. Some of these concerns can be addressed through the adoption of a more clearly defined decision-theoretic framework adapted to structural engineering safety issues. The components for such a framework have recently been outlined and are reviewed herein. It is argued also that structural engineering safety and reliability measures must be compatible with procedures adopted by other potentially hazardous industries.