Flutter Performance Study of Steel Truss Girder Suspension Bridge Under Large Angles of Attack

Wind characteristics are very complex over bridge site in complicated mountains area. And winds with large angles of attack are present easily. To investigate the flutter performance of long-span bridges under winds with large angles of attack, a long-span suspension bridge with steel truss girder located in deep-cutting gorge was regarded as an example. Through sectional model wind tunnel test, the flutter critical wind speeds of the original section were studied under winds with large angles of attack ranged from -7° to +7°.To specify the influence of aerodynamic measures, many aerodynamic measures were employed on the original section model to improve the flutter stability. Results indicate that the flutter critical wind speeds of the original section are relatively low under winds with angles of attack -5°~+3°.The influences of different aerodynamic measures such as closed central bridge deck, porosity of maintenance road, and the upper or lower central stabilizers on flutter performance are different under small and large angles of attack. At last, the closed bridge deck, the solid maintenance road, the upper and lower vertical stabilizers of proper height are adopted as aerodynamic measures, which can not only increase the flutter critical wind speeds to a large extent but also obtain lower drag coefficients. © 2019, The Editorial Board of Journal of Basic Science and Engineering. All right reserved.