GENERATION OF WIND LOADS ON A HORIZONTAL GRANDSTAND ROOF OF LARGE ASPECT RATIO

This paper reports wind tunnel data for a horizontal rectangular grandstand roof of aspect ratio 6.6:1. Wind pressures on the roof surfaces were measured and fluctuating normal forces on panels of the roof were obtained from real time integration of pressures. The results suggested that the distribution of roof pressures and panel forces is largely governed by flow separation patterns on the roof surfaces. Wind load variations with wind incidence angle were discussed with reference to the degree of suppression of separation on the bottom roof surface due to wind flow beneath the roof past the sloping grandstand. Spatial coherence measurements revealed large-scale organised fluctuations associated with flow separation, which were suggested to play an important role in the generation of roof loads.