LI Huan1,2,HE Xu-hui1,2,WANG Han-feng1,2,LIU Meng-ting1,PENG Si1,2
JOURNAL OF VIBRATION AND SHOCK. 2018, 37(7): 62-68.
π type cross-section of main beam vortex-induced vibration(VIV) is one of important factors influencing its wide-spread usage in long-span bridges. Taking a super high cable-stayed bridge with three towers as a certain engineering background, its VIV performances in a construction state were investigated with a sectional model in wind tunnel. Test results showed that the bridge suffers remarkable VIV within the designed wind velocity range; within the specified range of damping ratio in the code, amplitudes of the bridge’s VIV are larger than the specified value in the code; in order to suppress VIV of the main beam, flow-isolating plates and lower stabilizers are designed as aerodynamic vibration-reduction measures; the vibration-mitigation effect of flow-isolating plates seems to be limited, however, lower stabilizers have a better VIV-suppressing effect, they also satisfy the requirements of flutter stability. Finally, the mechanism for VIV-generating and suppressing was preliminarily discussed with CFD numerical simulation method.