Logarithmic Profiles and Design Wind Speeds

A simple procedure is presented for determining mean velocity profiles for purposes of structural design. The procedure is based on recent results of atmospheric boundary layer studies, for which a satisfactory theoretical, as well as experimental, foundation exists. It is shown that for high winds, e.g., these of interest to the structural engineer, the logarithmic law is valid up to heights of a few hundred meters. Similarity relations are used, on the basis of which it is possible to calculate wind speeds over built-up terrain if the wind speed over open terrain is known. Experimental data reported in the literature are presented, which confirm the validity of the procedure and suggest that the logarithmic law, widely recognized by meteorologists as an improvement over the power law, may supersede the latter for purposes of structural design.