Experimental investigation on wind loading of a stadium with a retractable roof

In the case of a building with a dominant windward opening, the internal pressure closely follows the external pressure at the opening, and the net roof pressures will be increased significantly which were normally larger than those derived from some codes. Currently for the structures with openings on the roofs, the internal wind pressure values were not provided in Chinese code. For the aim of structural designing as well as for the purpose of studying the effects of the wind loads on the main roof with retractable roof's opening, a rigid test model of a stadium with retractable roof was built with geometrical scale of 1:300. Wind tunnel tests were carried out to measure the wind pressures on the fixed roof and the retractable roof in turbulence flow. The characteristics of shape coefficient, mean wind pressure coefficient, fluctuating wind pressure coefficient and extreme wind pressure coefficients on the fixed roof and retractable roof were particularly studied. It is shown that retractable roof's opening reduces the mean wind loads on both the fixed and retractable roof greatly, and will make the main roof experienced positive pressures. In the case of retractable roof opening, the fluctuating wind loads of the fixed roof and retractable roof are increased, which compared to that of the closed case. For the retractable roof in opened condition, the extreme wind loads on both fixed and retractable roof will be decreased, and the maximum extreme wind loads will be present at the top opening of the fixed roof.