Wind Loads And Wind-induced Responses Of High-rise Overrun Building

Wind load is the main control load for the design of high-rise buildings, which affects the design stress of the cladding structure and causes the complex wind-induced response of the major structure. At present, with the continuous application of high-strengthening light materials,a large number of tall buildings with complex shape springs up. High-rise flexibility becomes the main characteristics of the structure and natural vibration frequency of structures is also closer to the dominant frequency of fluctuating wind. Thus, the structural dynamic responseis more significant. The method to accurately analyze the characteristics of wind pressure distribution and wind action on building surfaces and the law of wind-induced response obtained are essential prerequisite of the wind-resistant design of high-rise buildings efficiently.The current codes have not been explicitly specified for the wind-resistant design of super high-rise buildings.The calculation of wind-induced response only considers the effect of the first mode shape. Aiming at these problems, the following research is carried out on the basis of extensive research results demestic and abroad combining with the design of a super high-rise building:1. Based on CFD method of RANS and the RNG k-ε turbulent model adopted, the wind field of the super high-rise building is simulated, obtaining the characteristics of the wind pressure distribution on the facades under different wind directions. The results show that wind pressure distribution is associated with the wind. The maximum negative pressure of the building surfaces occurs for oblique direction and all appear in the corner. The maximum values of the positive pressure on the facades for all working conditions are basically equal.2. Based on fluctuation wind speed spectrum of Kaimal and the linear filtering method used, the simulation of the time-history Imitation of pulse pind load acting on high-rise buildings is generated. The results show that the software of Matlab using the linear filtering method and Kaimal wind speed spectrum can generate the fluctuating wind loadbetter.3. Based on the finite element software of Midas Gen, the time history analysis of along-wind vibration is performed for a certain transfinite high-rise building. The structural internal force, displacement and acceleration for different modes with Midas Gen are compared with those values with PKPM. The analysis shows that the time history analysis of the building with Midas Gen can obtain better resultsthan the values with PKPM. The calculation results still emphasis on safety with PKPM considering the first mode shape for wind resistance analysis of similar super high-rise building. The calculation need not to recheck with the second software. However, there exists significant error for the prediction of PKPM.The conclusions obtained in this paper can provide reference and guidance for the wind resistant design for similar super high-rise building.