Resilience-based optimal management of aging bridge networks under mainshock-aftershock sequences

This paper presents a mathematical framework for optimal management of aging bridge networks subjected to mainshock-aftershock sequences. The pre- and post-earthquake management of the highway systems is addressed considering performance objectives based on seismic resilience and life-cycle costs. Structural capacity of vulnerable bridges and traffic performance of the transportation network are investigated accounting for the effects of aftershocks by state-dependent fragility curves informing cumulative damage scenarios, and the effects of aging and deterioration process by time-dependent fragility curves. Optimal intervention sequences are identified under uncertainties involved related to bridge damage levels and mainshock-aftershock sequences based on a bi-objective optimization problem aiming at maximizing network resilience and minimizing costs associated with pre-event maintenance and retrofit interventions as well as post-repair restoration activities.