Serviceability wind risk assessment of tall buildings including aeroelastic effects

One issue that dominates the serviceability design of many modern tall buildings is wind-induced discomfort. The assessment of discomfort risk for the buildings occupants due to the wind action is, therefore, of primary importance. It can be properly carried out only through a reliable estimation of the acceleration responses which, particularly in the across-wind direction, may be influenced by aeroelastic effects. Within this context, a wide experimental campaign was carried out in this study in order to evaluate the wind-induced loads and responses of a continuous equivalent aeroelastic model of a regular square-section tall building. Measurements of surface pressures on 126 taps, overall forces, across-wind displacements and across-wind and along-wind accelerations were simultaneously carried out. Aeroelastic effects involving the across-wind response, which largely exceeds the along-wind one, are evaluated in terms of aerodynamic damping using an experimental-numerical procedure. Across-wind aerodynamic damping is found to take positive values for the model tested having high Scruton number. A general procedure for wind risk assessment of tall buildings related to comfort, in line with the Performance-Based Design (PBD) approach and the PEER (Pacific Earthquake Engineering Research [Center]) equation, is proposed and applied to a case-study building whose aeroelastic response is known from the wind tunnel tests performed.