Monitoring-Informed Life-Cycle Cost Analysis of Deteriorating RC Bridges under Repeated Earthquake Loading

This paper investigates the influence of rebars' corrosion monitoring systems on the vulnerability assessment and life-cycle cost analysis (LCCA) of reinforced concrete (RC) bridge piers subjected to repeated earthquake loading. A methodology is proposed to investigate the life-cycle economic savings gained with the use of a structural health monitoring (SHM) system made of corrosion sensors, exploiting the construction of damage-dependent fragility curves and using the pacific earthquake engineering research (PEER) equation to calculate the seismic probability of failure. The availability of corrosion sensors' data is accounted for in the degradation model for assessing the probability of failure by assuming that the recorded corrosion parameters are deterministic variables during the monitored period. Monitoring data are simulated by choosing values from the literature for the parameters representing the corrosion conditions. Seismic damage accumulation is considered through Monte Carlo (MC) simulations of long-term seismic scenarios considering the mean annual rate of earthquake occurrence obtained by the seismic hazard curves. The results of the methodology application to a case study highlight the importance of incorporating corrosion effects for the correct estimation of seismic life-cycle vulnerability. They are also used to discuss the advantage in terms of the safety and economy of including corrosion sensors for optimizing maintenance activities as opposed to purely inspection-based evaluations.