WIND-TUNNEL INVESTIGATION UPON THE COHERENCE OF PRESSURE MEASUREMENTS TAKEN AROUND A TALL BUILDING IN OPEN SITE TERRAIN

A series of wind tunnel tests were performed using a 1/250th scale model of a tall building, situated in open site terrain. Measurements of power spectra and coherence of the fluctuating pressure signals coming from static tappings positioned around the model faces were taken. Analysis of the data shows that, particularly on the leeward face, the levels of coherence measured are significantly less than predicted by the TVL method. This observation has important implications, since it may explain discrepancies between forces obtained from wind tunnel balance measurements, and pressure integration methods. Furthermore, differences between features present in the atmosphere and the wind tunnel may cause loads measured during a model test to be significantly less that those experienced by the full scale building.