Study on Wind-Induced Static Behavior and Buffeting Performance of a Long-Span Narrow Suspension Bridge in Mountainous Area
Horizontal deflectors are added to a narrow suspension bridge with steel-concrete composite stiffening girder in the mountainous area,to optimize its flutter and galloping oscillation performance.The static stability of the stiffening girder under average winds as well as the buffeting performance of the stiffening girder under fluctuating winds after the optimization were further studied to investigate various wind-induced static and dynamic effects and ensure the construction and vehicle travelling safety.Counting on the numerical simulations of the natural vibration characteristics of the full bridge and three-component coefficients and flutter derivatives of the stiffening girder via sectional model wind tunnel tests,a 3D nonlinear numerical modelling method was used to obtain the static critical flutter wind velocities of the stiffening girder before and after the aerodynamic shape optimization,and the results were compared with the calculations of the 2D theoretical analysis method based on small deformation assumption.A frequency domain method of buffeting response was used to calculate the buffeting displacement and internal forces of the stiffening girder under fluctuating winds,considering the described wind field characteristics at bridge site in the code.It is shown that after adding horizontal deflectors,the static stability of the bridge is sound and reaches the required level in the code.The buffeting displacement of the stiffening girder is increased to a degree,at the same time,the location of maximum vertical shear force in the stiffening girder is changed,and the torsional moment of the midspan cross-section is significantly increased,proving that the aerodynamic measure exerts limited effect on improving the buffeting responses of the stiffening girder.It is suggested to carry out further study on the fatigue performance of the bridge.
万方数据
维普
