Fragility curve development of highway bridges using probabilistic evaluation (case study: Tehran City)

Abstract

Seismic fragility analysis of bridges can be used to identify the probability of different damage states of bridges under earthquake hazards. This study aims to generate the fragility curve of highway bridges in Tehran, Iran, where these curves are not provided yet. To derive new fragility curves, the fragility curve of highway bridges from studies all around the world has been classified into different categories, based on their structural designs, bridge materials, country, and their analytical methods. A decision-tree analysis has been used to determine new fragility curves. The accuracy of these new curves was then assessed using a case study bridge and incremental dynamic analysis. The assessment analysis indicates that newly developed fragility curves for Tehran city have reasonable accuracy. The average difference between the derived fragility curve by the curves determined using Incremental Dynamic Analysis was acceptable. These new fragility curves helped to identify bridges throughout the Tehran city highways with higher seismic vulnerability. These can also be used for risk assessment and reducing seismic risk studies and future urban planning.