FORMULATION OF RISK-BASED DECISION UNDER UNCERTAINTY IN LIFE-CYCLE COST DESIGN OF INFRASTRUCTURES

摘要

The role of quantitative risk assessment (QRA) in the formulation of decisions under uncertainty is described for the optimal design of infrastructure systems. Optimal design may be determined on the basis of the minimum expected life-cycle cost, E(LCC); however, in order to minimize the effect of the epistemic uncertainty in the estimation of the LCC, a risk-averse value of the LCC may be designated to reduce the chance of under estimating the actual life-cycle cost. Similarly, a risk-averse value of the safety index may be specified to increase the confidence in the assurance of safety for the structural design. The systematic procedure for these purposes is illustrated with a hypothetical application in the determination of the retrofitted design height of the levee system in New Orleans to provide sufficient assurance of protection against flooding from future hurricane-induced surges.