Comparison of probabilistic methods for the effects of wind direction on structural response

• Published in: Structural safety 2020-11, Vol.87, p.101983, Article 101983
• Main Author: Holmes, J.D.
• Format: Article
• Language: English
• Subjects: Building; Buildings; Mathematical analysis; Multi-sector; Out-crossing; Probabilistic methods; Structural response; Tall; Tall buildings; Wind; Wind direction; Wind effects; Wind loads; Wind speed; Wind tunnels; Wind-load
• ISSN: 0167-4730; 1879-3355
• DOI: 10.1016/j.strusafe.2020.101983

•Three probabilistic methods of incorporating wind direction into predictions of wind loads are compared.•The assumptions and advantages and disadvantages of the methods are explained.•Variations of the outcrossing method are discussed and compared.•Application to a generic tall building orientated at eight different ways to a wind climate is used.•The multi-sector method is found to be the most reliable for the examples studied. This paper compares three methods for predicting extreme wind-load effects on buildings, allowing for the varying direction of the wind, as well as the windspeed itself. These are the ‘out-crossing’, ‘multi-sector’ and ‘direct calculation’ methods. Wind-tunnel data from a generic tall building, assumed to be located in Melbourne, Australia, at eight different orientations to the climate, have been used to assess the methods, and to compare the results with direct calculation of base moments. The out-crossing method gives reasonable results for about half the building orientations, but underpredicts the responses when the dominant northerly wind direction is not the major contributor to the response calculations. The multi-sector approach although slightly conservative for predictions at low values of average recurrence interval (ARI), is accurate for all responses examined at high values of ARI.