Earthquake damage estimation in Metro Manila, Philippines based on seismic performance of buildings evaluated by local experts’ judgments

Building damage due to a scenario earthquake in Metro Manila, Philippines is estimated based on seismic performance of the buildings evaluated by local experts’ judgments. For the damage estimation, building capacity curves and fragility curve are developed from questionnaire to the local experts of structural engineering. The Delphi method is used to integrate the experts’ opinions. The derived capacity curves are validated by comparing with the result of pushover analysis for typical buildings. Building responses due to simulated ground motions are estimated by the capacity spectrum method. Damage ratios are calculated from the fragility curves and the building responses. Distributions of the damaged buildings are computed by multiplying the damage ratios and the building inventory. The distribution and the amount of the damaged buildings in this study show significant difference from the estimation with the capacity curves of HAZUS, suggesting the importance of evaluation of the region-specific building performance.