Equivalent static wind actions on vertical structures

Since the pioneering studies developed by Alan G. Davenport, the equivalent static actions on structures are a key topic of the wind engineering research. Two main methods have been proposed. The former, referred to as the gust factor (GF) technique, defines wind actions through a unique load distribution scaled by a non-dimensional coefficient eventually depending on the effect considered. The latter, referred to as the load combination (LC) technique, defines wind actions, till now in the alongwind direction, as a combination of three distinct load distributions associated with the static, quasi-static and resonant parts of the response. This paper provides a rational scheme and a generalisation of these procedures with reference to cantilever vertical structures. As for the GF technique, also the LC technique is initially extended to the 3-D response, discussing critically a set of alternative models for the quasi-static part of the loading. A new method is also proposed, referred to as the global loading technique, where equivalent static wind actions are assigned as a unique load distribution independent of the load effect considered. All problems dealt with in this paper are solved in closed form.