Estimating life-cycle monetary losses due to wind hazards: Fragility analysis of long-span bridges

A numerical framework was developed for estimating the life-cycle monetary losses (maintenance and repair costs) due to wind-induced damage on a long-span bridge. The wind loading on the bridge deck was evaluated by means of flutter derivatives (FDs), which are measured in a wind tunnel test on a section-model of the deck. These aeroelastic coefficients are random due to experimental errors. A statistical approach was employed to evaluate the effects of this uncertainty source on the wind-induced response and the damage produced on the structure. first part of the study “fragility curves and surfaces” were used to estimate the exceedance probability of representative structural performance threshold indicators by accounting for experimental errors in the estimation of FDs. These thresholds were based on deck acceleration (for user comfort) and peak deck displacements (for structural damage). second part the results of the initial fragility analysis were used to analyze monetary losses, produced by wind loading. The proposed model for cost analysis was adapted from an existing life-cycle simulation algorithm for earthquake hazards. The pilot study employs a 1200-m suspension bridge model and data from wind tunnel experiments conducted at Northeastern University in the United States.