RANDOM AND FUZZY SET RELIABILITY ANALYSIS OF COASTAL STRUCTURES

In reliability analysis of coastal structures it is conventional to represent uncertainty in the basic variables describing the system as a precise joint probability distribution. Uncertainty in the limit state function is represented by introducing one or more additional random variables. This paper introduces two generalizations of the conventional approach. First it is illustrated how a range of types of uncertain information, not only information in the form of precise probability distributions, can be handled in reliability analysis. Second, fuzzy label descriptions of data are used to construct imprecise limit state functions. An example reliability analysis of a concrete revetment illustrates how the new approach can generate bounds on the probability of system failure.