ABSTRACT
Frequency and intensity of hydrological hazards have increased. Consequently, riverine bridges are suffering damage due to flooding. Fragility functions are used to estimate such damage conditioned on hazard intensity. However, flood fragility functions are limited for riverine bridges, and generally lack for masonry bridges. This paper presents a methodology to derive flood fragility functions for masonry arch bridges accounting for component failure modes. Demand and capacity of bridge components are derived from existing analytical expressions, and account for aleatory uncertainties via Monte Carlo simulations. The methodology is illustrated using a UK masonry bridge, which collapsed due to winter flood-induced scour. The investigated bridge is divided into its components (e.g., arches, pier) and a scour fragility function is derived for the arch, based on a lognormal cumulative distribution fitting to the derived failure probability data. Future research will develop scour fragility functions for other bridge components.
