ABSTRACT
The transformation of the knowledge about the natural wind, the structural response and the structural strength into criteria for the winds to be taken into account in the design of large bridges is described. The design winds depend on the failure mode – aerodynamic instability, overloading or fatigue failure – the natural randomness in the governing parameters and processes, and statistical and model uncertainties. Probabilistic methods are applied to determine the relevant design winds to achieve sufficient safety and reliability. The use of probabilistic methods also helps identify the most important uncertainties and gives the sensitivity of the reliability level to changes in input parameters. In a case study the critical design wind speed is determined for which a section model of the East Bridge across the Great Belt in Denmark in a scaled flow in a wind tunnel must be stable.
