桁架加劲梁悬索桥气动稳定措施试验研究

EXPERIMENTIAL STUDY ON THE AERODYNAMIC STABILITY MEASURE OF A SUSPENSION BRIDGE WITH TRUSS STIFFENING GIRDER

在山区峡谷大跨度悬索桥的建设中,由于受施工条件的限制,桁架加劲梁比钢箱梁在施工方面具有更好的优越性。但其扭转刚度以及气动稳定性能往往难以满足抗风要求。此时采用适当的气动措施则可以有效地提高其颤振稳定性。结合工程实例,对桁式加劲梁悬索桥桥面板中央开槽、中央稳定板、水平稳定板三种气动措施以及不同桥面板型式的制振效果进行了一系列风洞试验研究,得到了一些有益的试验结果,为该大桥的抗风设计提供了依据。

In the case of a super-long span suspension bridge across wide mountain valley, steel truss stiffening girder is more adaptable for the bridge section than steel box girder due to the limitation of construction condition. However, the torsion rigidity and aerodynamic stability of the steel truss stiffening girder usually does not meet the requirement of wind-resistance design. In such situation, the appropriate use of some aerodynamic measure may improve the flutter stability of the bridge obviously. So the detailed study on aerodynamic measures are useful and necessary for the aerodynamic safety of the bridge. Here in, Aizhai bridge, which is a super-long-span suspension bridge across deep valley, is taken as an example for investigation. Systematic wind tunnel tests are carried to investigate the validity of three different aerodynamic measures including central slot, central vertical stabilizer and horizontal stabilizer. The aerodynamic performances of two different bridge decks including concrete and steel in wind tunnel are investigated and compared as well. The presented outcomes give some profitable conclusions and provide guidelines for the wind-resistance design of Aizhai bridge.