Pre-Posterior Optimization of Sequence of Measurement and Intervention Actions Under Structural Reliability Constraint

When, based on the available information, an existing structure has an estimated failure probability above the admissible level, the default solution often is to either strengthen or replace it. Even if this practice is safe, it may not be the most economical. In order to economically restore and improve our existing infrastructure, the engineering community needs to be able to assess the potential gains associated with reducing epistemic uncertainties using measurements, before opting for costly intervention actions, if they become necessary. This paper provides a pre-posterior analysis framework to (1) optimize sequences of actions minimizing the expected costs and satisfying reliability constraints, and (2) quantify the potential gain of making measurements in existing structures. Illustrative examples show that when the failure probability estimated based on the present state of knowledge does not satisfy an admissible threshold, strengthening or replacement interventions can be sub-optimal first actions. An example shows that significant savings can be achieved by reducing epistemic uncertainties.