Post-Earthquake Bridge Repair Cost Evaluation Methodology

Post-earthquake repair costs are important for evaluating the performance of new bridge design options and different existing bridge configurations in the next major earthquake. Hazard and structural demand models provide information on the probabilistic structural response during earthquakes. Damage and decision models are needed to link the structural response to decisions on bridge repair actions and repair costs. A new step-by-step probabilistic repair cost methodology is proposed in this paper to evaluate the costs of repairs for different bridge components and the bridge as a system corresponding to varying degrees of damage. Repair actions, quantities, and costs are input into spreadsheet templates and a numerical tool evaluates expected repair costs and repair cost variance for a range of earthquake intensities. Central to the proposed methodology is the concept of performance groups—groups defined to account for bridge components that are repaired together. Six spreadsheets are used to track all of the necessary data: bridge information, structural response, component damage states, repair methods and repair quantities, and unit costs or production rates. Data can be customized for repair methods and bridge types particular to different state departments of transportation. The methodology is illustrated using repair cost fragilities for a typical multi-span reinforced concrete highway overpass bridge in California