Cost Assessment of Highway Bridge Network Subjected to Extreme Seismic Events

A transportation network is the economic backbone of a developed country. For that reason, it is important that the network maintain functionality after catastrophic natural events and minimize downtime to reduce adverse effects on society and the economy. A holistic framework that integrates seismic risk, vulnerability of system components, and a traffic model is developed. This framework is used to evaluate the direct and indirect costs associated with extreme seismic events. The combined effect of ground motion and liquefaction is considered to estimate the seismic risk of the system. Bridges are considered the most vulnerable network components. The concept of fragility curves is used to combine the probability of bridge failure with the postevent functionality of the network. An integrated traffic model is used to predict route choices after an earthquake. Finally, the developed framework is used to estimate the earthquake risk of the test bed transportation network in the San Francisco Bay Area of California. The direct and indirect costs associated with several earthquake scenarios in the region are estimated, and annual risk curves are developed.