Arte Verde Marista Goiania – Brazil
A wind tunnel study of the structural loads and building motion was undertaken for this slender 158-metre-high residential tower in Goiania, Brazil (slenderness ratio 1:13). To perform these studies, Windtech conducted a detailed wind climate analysis for Goiania region and combined the wind data with pressure coefficients derived from wind tunnel test. Testing was carried out using a 1:200 scale model fitted with a total of 328 pressure sensors spread across the external façade. Wind loads on the tower structure were derived from the measured directional external pressures acting on the façade using the High-Frequency Pressure Integration (HFPI) technique, which enables an accurate determination of the wind loads and equivalent static load cases. The results obtained from the wind tunnel test, including the tower’s dynamic cross-wind response, were compared with estimates from several wind codes. The Brazilian wind code (NBR6123:1988) may underestimate the cross-wind response, given that it does not consider excitation by vortex shedding.
Additionally, occupant comfort due to building motion was assessed by comparing the acceleration and rotational velocities of the building with appropriated comfort criteria. In order to improve occupant comfort, torsional stiffening was required. Windtech recalculated the wind loads acting in the reinforced structure and reanalysed the occupant comfort levels, which proved to be satisfactory.