Theoretical methods for .dynamic alongwind force estimation are examined by means of comparing with wind tunnel experiment results, and empirical formulae for static and dynamic wind forces are proposed. It is found that (1) theoretical methods can not be guaranteed the reasonable accuracy for any of considered sectional type of 3-D cylinders with height to root of sectional area ratio of 4.0, and (2) Simiu's assumption that perfect correlation of wind forces between windward and leeward face may lead to an overestimation of dynamic wind force is not always appropriate, although his proposition has been widely adopted through many experimental and full-scale measurements. The proposed empirical formulae provide reasonably accurate input forcing function for preliminary design of isolated tall building with various geometrical conditions.
