Life-cycle reliability assessment of reinforced concrete bridges under multiple hazards

Abstract

This paper proposes a novel probabilistic methodology for estimating the life-cycle reliability of existing reinforced concrete (RC) bridges under multiple hazards. The life-cycle reliability of an RC bridge pier under seismic and airborne chloride hazards is compared to that of a bridge girder under traffic and airborne chloride hazards. When conducting a life-cycle reliability assessment of existing RC bridges, observational data from inspections can provide the corrosion level in reinforcement steel. Random variables related with the prediction of time-variant steel weight loss can be updated based on the inspection results using Sequential Monte Carlo Simulation (SMCS). This paper presents a novel procedure for identifying the hazards that most threaten the structural safety of existing RC bridges, as well as the structural components with the lowest reliability when these bridges are exposed to multiple hazards. The proposed approach, using inspection results associated with steel weight loss, provides a rational reliability assessment framework that allows comparison between the life-cycle reliabilities of bridge components under multiple hazards, helping the prioritisation of maintenance actions. The effect of the number of inspection locations on the updated reliability is considered by incorporating the spatial steel corrosion distribution. An illustrative example is provided of applying the proposed life-cyle reliability assessment to a hypothetical RC bridge under multiple hazards.

Keywords:

• Life-cycle reliability
• inspection
• steel corrosion
• updating
• seismic hazard
• airborne chloride hazard
• traffic load
• multiple hazards
• spatial variability

Acknowledgements

This work was supported by JSPS KAKENHI grant number JP 16H04403. The first author was supported by The 100th Anniversary Chulalongkorn University Fund for Doctoral Scholarship and The 90th Anniversary of Chulalongkorn University Fund (Ratchadaphiseksomphot Endowment Fund). The opinions and conclusions presented in this paper are those of the authors and do not reflect the views of the sponsoring organisations.