20th Australasian Fluid Mechanics Conference Perth, Australia 5-8 December 2016 Integration of Wind Tunnel Pressure Measurements with the Structural Model for a New Zealand Stadium Roof A. McBride 1 , R.G.J. Flay 2 , T. Stuart 1 , J.B. Davidson 1 , D.J. Le Pelley 3 , B.J. Davidson 1 , Y.F. Li 2 1 Compusoft Engineering Limited, Auckland 1023, New Zealand 2 Department of Mechanical Engineering, University of Auckland, Auckland 1142, New Zealand 3 Doyle Sailmakers, Auckland 1746, New Zealand Abstract Wind tunnel tests were performed on a 1:200 scale model of the long span west stadium canopy proposed for QBE Stadium in Auckland. The tests measured the pressures on the proposed roofing elements. These were then processed into pressure coefficients based on the tunnel wind speed. Selection of critical load cases was carried out by integrating for key metrics for this structure, defined as maximum base shears and overturning moments for the whole structure. The wind tunnel pressure data results for these critical load cases were then integrated directly with the structural analysis model. This approach enabled 10 unique load cases to be determined. It was found that this was a very effective way of determining the wind loads and designing an efficient structure to resist them. Introduction The QBE stadium is located 17 km north of the Auckland CBD at Albany. In order to increase its utility, Stadiums Auckland is investigating roofing it completely. This comprises a new roof above the west stand to be built in phase 1, and an openable central roof section which completes the stadium enclosure to be built in phase 2. Wind loads are crucial to the design and thus wind tunnel tests were commissioned in order to obtain loads for various design configurations. The wind tunnel investigation was carried out in the boundary layer wind tunnel at the University of Auckland’s Newmarket Campus on a 1:200 scale model of the long span west stadium canopy proposed for QBE Stadium in accordance with the requirements of the Australasian Wind Engineering Society quality assurance manual [1]. The tests measured the pressures on both the existing and proposed roofing elements. The paper relates to the results from the modelling of the new phase 1 canopy, as well as the analysis including  A description of the proposed structure to be built in phase 1.  Estimation of the design loads using conventional ‘Code’ approaches, i.e. AS/NZS1170.2 [2].  Processing of the wind tunnel data for implementation into an analysis model.  A description of the process adopted for the selection of appropriate design load cases.  Analysis and design of the structure. It is anticipated that additional work will be published that will look at the interpretation of the wind tunnel data on the existing roof, as well as dynamic sensitivity and interpretation of results for fatigue assessment of the structure. Description of the structure The west stand canopy comprises a 250 m span leading edge tri- chord steel truss that rises to 40 m above pitch level at mid-span. From this truss a total of 12 radial tri-chord trusses in turn span down to the ground level behind the west stand embankment. All structural steel truss elements are to be fabricated from circular hollow sections of varying sizes that have been optimised according to the loading demands derived from wind tunnel testing. The steel structure is then clad with a combination of tensioned PVC architectural membrane fabric and glass fibre, fluo-polymer reinforced membrane fabric. The total area of the tensioned membrane is 7,800 m 2 . The maximum width of the structure at the mid-line is approximately 55 m and is kept elevated above the ground and embankment levels to ensure air flow under the structure. Because of the extent of the structure a number of rear props have also been introduced to assist with the structural integrity. The general structure located on the site is illustrated in figure 1. Underlying the stadium are layers of alluvium material varying in depth which in turn overlay the bedrock horizon and hence all foundations to the canopy are piled to bedrock. Understanding the interaction of the superstructure with its foundation system is an integral step in the process of understanding the whole structure’s response to wind loading. At the time of writing, construction is targeted to commence in the fourth quarter of 2016 or the first quarter of 2017. Figure 1. Rendered view of west canopy (in the background) at the site. Site specific wind speed estimation using AS/NZS1170.2:2011 The site is located in region “A6” as categorised by the Loadings Standard which gives rise to a regional wind speed,  ோ , equal to 46 m/s for the prescribed annual probability of exceedance as per AS/NZS1170.2 [2] (= 1/1,000) for the Ultimate Limit State