Investigation Of Blowing Control Over The Wind Loads And Wind-induced Responses On A Super High-rise Building

With the development of construction technology and extensive application of new materials and structure systems, super high–rise buildings have been experiencing an unprecedented construction peak in the past few years. With large aspect ratio and low damping ratio, the super high-rise buildings are very susceptible to wind loads. For a super high-rise building whose height is more than200m, the wind loads instead of earthquake action will become the dominant factor in its structural design. What’s more, in the process of wind-resistance design for high-rise buildings, it is usually easy to meet strength requirements, but difficult to meet displacement requirements and comfort criteria. Therefore, we need to take measures to mitigate the wind loads and wind-induced responses of super high-rise buildings. Based on the principle of aerodynamics, blowing control is newly considered to improve the wind-resistance performance of super high-rise buildings. Although some researches have been carried out via numerical simulation, the super high–rise buildings controlled by the upper-surface blowing should be investigated by carrying out wind tunnel test and wind-induced response analysis. Therefore, the main contents in this dissertation are shown as followings:1. Based on the existing experimental techniques about suction/blowing control, pressure measurement tests of a super high-rise building under upper-surface blowing control have been carried out. Based on the results of wind tunnel test, effects of orifice geometrical parameters (including blowing angle and slot position) and blowing velocity are analyzed, and coefficients of wind load reduction are calculated to quantify the blowing control effects.2. Computational fluid dynamics (CFD) models of the super high-rise building controlled by upper-surface blowing are established using the commercial software FLUENT, and the numerical results are obtained using both the Reynolds-averaged Navier-Stokes (RANS) method based on the Reynolds stress equation model (RSM) and the large eddy simulation (LES) method. Compared with the results from wind tunnel tests, the reliability of numerical simulation method is validated. By showing the detailed flow field around the CFD models, mechanism of blowing control for the wind loads is clarified.3. In order to investigate the effects of blowing control on the wind-induced responses, steel structural analysis model for the super high-rise building is established corresponding to the wind tunnel test model, and wind-induced responses are analyzed using commercial software ANSYS. Finally, the coefficients of vibration reduction are calculated to compare the wind-induced responses (such as top displacement, story displacement, top acceleration, base shear force and moment) of the blowing controlled models and uncontrolled model (basic model).