ABSTRACT
This paper introduces a probabilistic framework for optimizing retrofit decisions using a risk-based real options approach. By adopting the concept of real options, the framework systematically incorporates flexibility into decision-making under uncertainty. It begins with a time-dependent seismic risk assessment that evaluates structural deterioration processes both with and without retrofit measures. The results of this assessment are then integrated with real options analysis. An optimization problem is subsequently formulated to maximize the real option value for a given bridge column retrofit method, thereby identifying the optimal retrofit application times. A case study involving deteriorating reinforced concrete bridge columns demonstrates the practical application of the framework. The study also examines how key parameters related to risk and real options analyses influence optimal retrofit planning.
