Fragility estimates for the Fabela Bridge in Mexico incorporating vibration field data

This study represents fragility estimates for the Fabela Bridge, a five-span concrete bridge in Toluca, Mexico. Vibration tests are conducted on the bridge and based on the recorded accelerations, vibration frequencies of the bridge are computed. Preliminary estimates of the structural properties of the bridge such as stiffness of bridge components are obtained from available information in design drawings. These properties are then updated by matching the vibration frequencies of a finite element model of the bridgewith the frequencies obtained from field data.The updated structural properties better reflect the actual conditions of the bridge and incorporate the effects of potential deterioration.Updated properties are used to estimate theshear and deformation capacitiesof each column in the Fabela Bridge and the corresponding seismic demands. Deformation and shear modes of failure for each column of the bridge are considered in the probabilistic models and fragility of the bridge for given spectral acceleration. Fragility curves are developed at both component and bridge levels.