Alongwind Static Equivalent Wind Loads and Responses of Tall Buildings. Part I: Unfavorable Distributions of Static Equivalent Wind Loads

Although on the same theoretical basis, the current standards of major countries have set out two evidently different distributions of along-wind static equivalent wind loads, one is the same as the mean wind force and the other is the same as the first mode shape, on tall buildings. In this paper, the fluctuating static equivalent wind load is evaluated as mean, background and resonant components, and the unfavorable distribution of each component is separately addressed. Meanwhile, the wind loads by the above two code methods are derived. The effects of the wind loads by the two code methods on tall buildings are then examined to identify whether or not they are equivalent with regard to the actual wind induced responses. The results show that the wind loads by the two code methods can only ensure an equivalent first mode displacement response, and they may lead to some considerably unfavorable load effects, for example, the base shear force estimation. At last, a numerical example demonstrating the main results is given.