WIND LOADS AND EFFECTS OF RIGID FRAME BRIDGES WITH TWIN-LEGGED HIGH PIERS AT BALANCED CANTILEVER ERECTION STAGES

This paper presents a theoretical model of rigid frame bridges with double thin-wall piers during balanced cantilever erection stages with consideration all wind effects both on the beam and the piers. The wind loads of the model include the mean wind load and the load induced by all the three turbulence components and by the vortex shedding. Based on the stochastic vibration theory and the frequency-domain method, the response of the mean wind load and the background response of the fluctuating wind load are calculated by using the influent function. The resonant response of the fluctuating wind load are calculated by using the main mode shapes of the structure. The theory and formulations are proposed in this paper, and were verified by the 3rd pier of the Xiaoguan Bridge. The numerical results show that the effects of different loading components are different, and the results will be more security and accurate if the effects of each loading component were considered.