The Research On Wind-induced Response And Equivalent Wind Load Of Tall Building

With the development of economy, the progress of science and technology, and the increment of the population in cities, tall buildings have been greatly developed in the last thirty years. The current status and future trends of this development make the wind-induced effects on tall buildings as one of the most important effects affecting the buildings'safety, serviceability and economy, so the research of the wind-induced effects is very important in the design of tall building. In this thesis, based on wind tunnel tests of two typical tall building, the wind-induced responses are calculated, through comparing with the results which are calculated by following wind load codes, the differences and the reasons of resulting differences are analyzed. At the same time, the wind-reduced responses, the influence of incident wind directions and the surrounding environments on the equivalent wind loads, and the wind load changing with the wind direction are studied. This study mainly contains the following:First of all, the analysis method of wind-induced responses based on the theory of random vibration and the classic design method– gust load factor method are introduced. In the ISO standard and the wind load codes of America and Japan, the wind-induced vibration coefficient is called gust effect factor and is a constant, whereas it is a parameter changing with the elevation of the structure in the China'code. The reason is that the gust effect factor is a wind-induced vibration coefficient of displacement, but in the Chinese code, it is a wind-induced vibration coefficient of inertia force. Then based on two examples of specific projects, the based shear and based moment are determined in accordance with the four wind load codes.Then based on wind-tunnel test results of the two building, the variations of the wind-induced acceleration response, the equivalent wind loads, and the internal force with the approaching wind direction changing are investigated. In addition, effects of the turbulence intensity and surrounding conditions on the wind effects on the two building are presented and discussed in detail.Finally, the pressure data without the surrounding conditions are analyzed; on the base of the analysis, the variations of wind load spectra with the incident wind direction are discussed, and the coherences of the wind-induced pressures are studied.