Bridge Functionality Relationships for Improved Seismic Risk Assessment of Transportation Networks

Relationships between bridge damage and the resulting loss of functionality of the bridge are critical to assessing the impact of an earthquake event on the performance of the transportation network. This study addresses this data need by use of a Web-based survey of central and southeastern U.S. Department of Transportation bridge inspectors and officials. Results of the 28 responses are analyzed and offer a link between various types of bridge component damage and the expected level of allowable traffic carrying capacity due to closure decisions and repair procedures. This data is utilized to assess the probability of meeting various damage states, expressed in terms of restoration of functionality, and subsequently facilitate the refinement of component limit-state capacities for analytical fragility curve development. The bridge functionality relationships and methodology outlined serve as the basis for refinement of critical tools in the seismic risk assessment framework and improved assessment of transportation network performance.