Probabilistic seismic loss estimation of aging highway bridges subjected to multiple earthquake events

Abstract

This study investigates the seismic life-cycle cost of aging highway bridges under chloride exposure when subjected to multiple main shock earthquake events along the design lifetime of the structure. While chloride induced corrosion manifests as a continuous deterioration process, earthquake occurrences are typically intermittent. Although relatively weak seismic events that induce none-to-minor bridge damage may not instigate immediate intervention and repair, resulting structural cracks may further accelerate the corrosion process. This study presents a novel Monte Carlo based methodology that explicitly considers potentially altered deterioration pattern between seismic shocks as well as uncertainty in earthquake occurrences, record-to-record variability, repair decisions and repair processes for seismic life-cycle cost computations. The proposed framework also eliminates the need for the often improbable assumption in past literature on seismic life-cycle cost assessment that necessitates structural rehabilitation to pre-hazard states regardless of the seismic damage level. Case-study application of the proposed framework is demonstrated on a single column integral bridge located in the marine splash zone in California, United States. Results from multiple main shock analysis of both non-deteriorating and aging case-study bridge reveals a significant contribution of cumulative damage from corrosion deterioration and shock sequences towards seismic loss and life-cycle cost assessment.

Keywords:

• Aging highway bridges
• corrosion deterioration
• Monte Carlo simulations
• multiple earthquakes
• seismic life-cycle cost
• uncertainty analysis

Acknowledgements

The authors would also like to acknowledge the anonymous Reviewer 3 for his/her review comments that has led to incorporation of several practical aspects pertaining to seismic loss estimation of deteriorating highway bridges.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors acknowledge the financial assistance provided by the Ministry of Human Resource Development (MHRD), Government of India (GoI), and Department of Science and Technology (Grant No. ECR/2016/001622) for the research work at Indian Institute of Technology Bombay.