钢桁架悬索桥颤振稳定性能研究

Flutter stability of a steel truss girder suspension bridge

钢桁架悬索桥由于抗扭刚度较小其颤振稳定性通常难以满足抗风稳定性要求。以刘家峡大桥为例通过风洞试验研究了采取中央稳定板、导流板、封闭防撞栏等气动措施组合对钢桁架悬索桥颤振稳定性的影响。结果表明:上、下稳定板同时使用效果优于单独使用;将上稳定板做成分段布置时,正攻角的颤振临界风速会急剧降低。水平导流板外置比导流板内置于钢桁架内部效果好;加宽水平导流板可以使不同攻角颤振稳定性趋于均衡。加高并封闭防撞栏杆可以起到中央稳定板的作用,能有效提高桁架悬索桥不同攻角的颤振临界风速。

The flutter stability of a steel truss girder suspension bridge usually does not meet the requirement of wind-resistance stability as it has a lower torsion rigidity. Based on Liujiaxia Bridge, wind tunnel tests were performed to investigate the effects of different aerodynamic measures including central stability boards, a guide vane and a closed crash barrier on the flutter stability of a steel truss girder suspension bridge. The results showed that the upper central stability board and the lower central stability one used at the same time are better than they used separately; the flutter critical wind speed with positive wind attack angle decreases sharply when the upper central stability board is separated into segments; the guide vane placed outside the truss girder is better than it placed inside the truss girder; the flutter stability with different wind attack angles becomes more balanced when the guide vane is widened; a crash barrier heightened and closed can play the same role of the central stability board, it can raise the flutter critical wind speed of a steel truss girder suspension bridge with different wind attack angles effectively.