Wind Induced Loads And Effects On Rectangular Tall Buildings

With the development of economy and progress of science and technology and the increase of population, more and more tall buildings have come to appear in modern cities. Due to the aerodynamic interference of neighboring buildings, wind loads on tall buildings are considerably different from those on isolated buildings.Taking the Qianjiang New town complex Project (Phase I) Sun Hung Kai China Resources as the background. This thesis presents detailed studies on wind loads on the isolated rectangular building with different section breadth depth ratio(BDR) in terrain type B of GB50009 using the synchronous wind pressure measurement method. Wind loads on the building with BRD of 2:1 under wind action with interference effects from one and two identical surrounding tall buildings were also investigated. The main content and conclusion of this study can be summarized as follows.Effects of BDR on mean and peak wind pressure coefficients, shape factor and total base wind induced load coefficients in different azimuth were firstly analyzed. The results show that the BDR can significantly affect the shape factor in the controlling wind direction when elevation of the building normal to the wind direction, and a maximum shape factor was found up to 1.47, which is significantly greater than that of 1.3 proposed by GB50009 for square section building, when the section BDR is 1.5. Empirical formula was proposed to predict the shape factor for different section BDR.For mean interference effects, the results show that the upstream interfering buildings generally play shedding effects on the interfered building. The surrounding side by side or downstream interfering buildings can reduce the positive wind pressure on the windward face of the interfered building due to blocking, but at the same time, negative wind pressure on the leeward face also was significantly amplified, and as a result, the net wind load in the along wind direction was enhanced finally. At the controlling wind direction of 0 degree, results show that the wind induced vibration response is generally controlled by the background response which indicates the wind induced peak shear, bending moment and also the interference factor(IF) were independent of the wind speed at the calculated basic wind pressure range of 0.4kPa to 0.9kPa. The results show that adverse interference effects were also found when interfering buildings were located at the specific downstream positions, and the peak base moment under the action of the interfering buildings at the skew wind may greater than that of the isolated building at the wind direction 0°.