ABSTRACT
ABSTRACT. The concepts involved in specification by performance are outlined and the pressures driving engineers towards this form of specification are discussed. The differences between the requirements which govern the design of concrete coastal structures as opposed to general building construction are reviewed. Specification of design and construction by performance requires a clear understanding of what performance is to be achieved in a defined time, to a defined probability. At present, the life of a structure is only a notional concept. More specific application to coastal structures of “design working lives", now introduced in Eurocode 1, is presented. Specification of design parameters for structural design is considered, because the probabilistic basis of environmental loading interacts with the definitions of and probabilities of failure within the operating life, and requires to be defined. Developments in specification for durability are reviewed, in particular in relation to deterioration mechanisms specific to coastal structures. It is concluded that analytical models for design to a defined life, and accelerated test methods, are a much needed development but that responsibility for performance achievement cannot, at least at present, be specified for contractual compliance.
