Engineering spectra over water

For many civil engineering structures on the sea dynamic wind loading caused by the atmospheric turbulence is a serious concern for the designer. Gust loading on streamlines bridge decks requires knowledge of the vertical wind field fluctuations not only in one point, but also how the fluctuations are correlated in space (Simiu and Scanlan 1996; Larose, Mann 1998).

Also the horizontal components may be of importance in bridge aerodynamics. For dynamical load calculations on a wind turbine at an off-shore location knowledge of all three wind components and their spatial correlations are needed because the gusts are ‘sampled’ in a complicated way by the sweeping blades.

Yet other structures such as tension leg platforms used for extracting oil on deep waters are sensitive to slow variation in the direction of the wind. Thus various engineering structures are sensitive to various components of wind fluctuations at a wide range of frequencies and also to the spatial correlations of these fluctuations.