New Fragility Curves for Evaluation of the Vulnerability of Bridges to Earthquakes in Iran

Abstract

Bridges are vulnerable structures in transportation networks, as demonstrated by the results of recent earthquakes worldwide. Their failure can lead to disruptions in the functionality of road networks and cause delays in emergency response and recovery after earthquakes. Researchers have developed different fragility functions to assess the vulnerability of bridges to earthquakes. However, suitable fragility curves are not available for many types of bridges for seismic-risk assessment of transportation networks. The current study presents new fragility functions for four common bridge categories in Iran. For this purpose, existing fragility curves were collected through a systematic literature review according to the bridge typologies. The analytical hierarchy process was used to adjust the collected functions for the case of Iran based on expert opinion, considering local practices, bridge similarities, and construction quality. The newly developed fragility functions were validated by converting the data to vulnerability curves and comparing them to the damage observed to bridges from past earthquakes in Iran and other countries under similar conditions. The results revealed that, for over 50% of the evaluated damaged bridges, the relative error in vulnerability curves for estimating the loss ratio was below 20%.

Keywords:

• bridge damage
• fragility curve
• seismic risk
• transportation networks
• vulnerability

Acknowledgements

This study is completed as a partial fulfillment of a research project entitled as “Developing a model for risk assessment of urban roads with an emphasis on physical and social parameters” (Project no: 796-8336) under the auspices of the International Institute of Earthquake Engineering and Seismology. The authors would like to thank all scientists and engineers who provided their expert opinions, especially Mr. Iman Salehi for his generous technical support.

Disclosure Statement

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

Supplemental Data

Supplemental data for this article can be accessed http://dx.doi.org/10.1080/10168664.2024.2318323.

Author Contributions

All authors contributed to the completion of this study. Material preparation, data collection and analysis were performed by Vahideh Shirvani Harandi under the guidance and supervision of Babak Mansouri and Kambod Amini-Hosseini. The first draft of the manuscript was mainly written by Vahideh Shirvani Harandi and all authors commented on previous versions of the manuscript and contributed to modifying and finalizing the manuscript. All authors read and approved the final manuscript.

Data Availability

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.