Study of Variation in Wind Loads on Rectangular Cross-section Tall Building due to Change in Location of Interfering Buildings

Modification of wind pressure distribution on a principal tall building having a rectangular cross-sectional shape is studied in the present research work due to the presence of closely located interfering buildings having variable positions. The study intends to understand the phenomenon of wind interference for commonly adopted rectangular cross-section tall buildings and hence provide useful information to practicing engineers and architects. Wind tunnel experimentation is undertaken with interfering buildings having the same height and shape of cross-section as that of the principal building. Interfering buildings are closely placed in front of the principal building, with two interfering buildings kept normal to the principal building at its two ends initially forming a U-shape in the plan. The position of interfering buildings is varied in two ways: (1). Both the interfering buildings are moved simultaneously toward each other in the across wind direction. (2). One of the interfering buildings is kept stationary in its position while the position of the other is varied in the across wind direction. Two types of measurements are conducted independently for variation in position: (1). Force Measurement and (2). Pressure Measurement. Obtained experimental results from the two independent measurements are compared later for the purpose of validation. Interference factor is used for expressing force measurement results, while pressure measurement results are expressed in terms of mean and RMS wind pressure coefficient (CP and C-P(')). It is observed from force measurement that the across wind force for the principal building gets enhanced to as high as 2.18 times that for isolated condition and the twisting moment gets increased significantly to a value as high as 39.43 times that for isolated condition. Contour plots for the coefficient of mean wind pressure explain distinctly the reason for obtained results under force measurement. Also, they precisely show the wind pressure distribution across different vertical faces of the principal building which can be utilized for the design of the facade and other building components. The experimentation results distinctly present the best possible position of interfering buildings that shall be considered with respect to the wind loads and also gives caution for some other positions of the interfering buildings.