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

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.