Standards Australia/Standards New Zealand has released the newest edition of “Wind Actions on Structures” under the new designation AS/NZS 1170.2:2021. This document will supersede AS/NZS 1170.2:2011.
The standard provides wind actions for use in the design of structures subject to wind action, according to Windtech, which participated in the standard’s wind loads sub-committee. The standard provides a detailed procedure for the determination of wind actions on structures, varying from those less sensitive to wind action to those for which dynamic response are to be taken into consideration.
The objectives of this revision are to remove ambiguities, and to incorporate recent research and experiences from recent severe wind events in Australia and New Zealand.
Some of the changes to the standard include:
· Updates to the cross-wind force spectrum coefficients for the cases of towers having a height to width aspect ratio greater than 3.
· Introduction of a simple and reliable method of deriving the rotational velocity and tortional acceleration from the resonant dynamic component of the along-wind response.
· Guidance on how to determine design load cases in the form of combination factors for the along-wind, cross-wind and torsion components. This is presented in the form of a total of 4 load cases for buildings less than 70 meters in height and 12 load cases for buildings taller than 70 meters.
· A simplified wind speed map for the southern part of Australia.
For a preview of the standard and more details on this story, go to Standards Australia/Standards New Zealand.