A flood loading methodology for bridges

A revised Australian Bridge Design Code is due for publication in 1990, and will include limit states design philosophy. The bridge designer will be required to investigate a range of flood events, and the accurate prediction of flood loads requires realistic values of drag coefficients and design velocities. The paper reviews research into hydrodynamic bridge loads and examines current and proposed flood loads specified in Australian bridge design codes. New model testing equipment for hydrodynamic load determination at the University of Queensland is described as well as proposed bridge model geometrics being investigated. Formulae are presented to calculate maximum flood velocities based on previous work by Vanoni for steady uniform flow conditions. Guidance is given in the form of a flood loading methodology to enable the designer to calculate the critical design flood forces for a range of flood events (A).