Structure and Infrastructure Engineering · 2009 · 115 citations · 7 references
EngineeringCivil EngineeringBridge EngineeringEarthquake EngineeringTransportationBridge DesignBridge RetrofittingInfrastructure RestorationSeismic Retrofit Of StructuresStructural RetrofittingTransportation EconomicsBridge RetrofitRetrofit Cost AnalysisSeismic PerformanceSeismic Performance Of BridgesSeismic RetrofitSeismic Retrofit Of BridgesSocial Cost AssessmentSocio-economic Impact Assessment
The study evaluates the socio‑economic impact of seismic retrofitting bridges in the Caltrans Los Angeles highway network through simulation. Using 47 USGS‑consistent earthquake scenarios and pre‑ and post‑retrofit fragility curves, the authors simulated network performance, estimated driver‑delay and opportunity‑loss social costs, calculated present‑value benefits from avoided losses and repair costs, and compared these benefits to retrofit costs to assess the benefit‑cost ratio. Results indicate that, from Caltrans’ perspective, seismic retrofitting is cost‑effective when social‑cost avoidance is included. The work was funded by Caltrans (contract RTA‑59A0304) and the Federal Highway Administration (contract DTFH61‑98‑C‑00094) through the MCEER.
Abstract A simulation-based study is performed to evaluate the socio-economic effect of seismic retrofit of bridges using the California Department of Transportation (Caltrans) Los Angeles area highway network as the testbed. 47 scenario earthquakes that represent the regional seismic hazard, consistent with the US Geological Survey (USGS) hazard map, are considered. Two sets of bridge fragility curves, before and after seismic retrofit, are used to simulate the seismic performance of the network in both cases. Analysis estimates the total social cost arising from driver delay and loss of opportunity in the degraded network. The benefit of seismic retrofitting is computed in present values as equal to the total future economic losses avoided from social cost and repair/restoration cost over the remaining bridge service lives. Estimated benefit is compared with the retrofit cost to investigate the benefit-cost ratio. Study shows that from the Caltrans point of interest, bridge seismic retrofit is cost-effective when loss avoided due to social cost is considered. Keywords: highway transportation systemseismic retrofitdriver delayloss of opportunityeconomic analysisbenefit-cost ratio Acknowledgements This study was partially supported by California Department of Transportation (Caltrans) under contract RTA-59A0304 and by Federal Highway Administration under contract DTFH61–98-C-00094 through the Multidisciplinary Center for Earthquake Engineering Research (MCEER) in Buffalo, NY.
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