Nonuniform wind characteristics and buffeting response of a composite cable-stayed bridge in a trumpet-shaped mountain pass

Abstract

Due to the spatial differences in wind fields in mountainous areas, it is an urgent problem to accurately estimate the buffeting response of long-span bridges in mountainous areas. In this paper, the spanwise variations in the mean and fluctuating wind characteristics of a bridge site are obtained based on a terrain wind tunnel test of a trumpet-shaped mountain pass. Additionally, the aerodynamic admittance function of a Π-shaped composite girder under different wind attack angles is measured in the wind tunnel. The buffeting response calculation theory considering the spanwise variations in the mean wind and fluctuating wind characteristics along the main girder is established. The influence of the nonuniform wind characteristics on the buffeting response of the main girder is analyzed. The results show that the spanwise variation in wind characteristics at the bridge site is affected by the direction of inflow and can be described by a quadratic polynomial. Nonuniform wind parameters have obvious effects on the buffeting response, and a nonuniform wind attack angle is a key factor affecting the buffeting response. It may not be appropriate to predict the buffeting response by using the single-point wind field observation results in mountainous areas.