I. B. Kroon

Optimal reliability-based code calibration

Abstract Calibration of partial safety factors is considered in general, including classes of structures where no code exists beforehand. The partial safety factors are determined such that the difference between the reliability for the different structures in the class considered and a target reliability level is minimized. Code calibration on a decision theoretical basis is also considered and it is shown how target reliability indices can be calibrated. Results from code calibration for rubble mound breakwater designs are shown.

Sensitivities in Structural Maintenance Planning

A general description of optimal inspection and maintenance planning based on the classical decision theory and the modern reliability theory is given. A number of simplifications to this description is given leading to more appropriate formulations for practical applications. Sensitivities of both optimal inspection and maintenance plans as well as the associated costs are given with respect to the assumptions on which the planning has been performed. These sensitivities indicate the significance of the individual assumptions and may be used as a decision tool to reject particular optimal inspection and maintenance plans showing too large sensitivity. An example from the offshore industry is given to indicate how the methodologies can be used in practical applications.