Buffeting performance of long-span bridges with different span affected by parametric typhoon wind

Abstract

Currently, typhoon-related performance of long span bridges usually focus on a specific wind record such as wind speed and turbulence intensity during a full typhoon, however, the inter-correlation among wind characteristic parameters under typhoon wind climate is ignored. The existing investigation about structural responses during typhoon attacks are still limited at case-study analysis, and hardly provide a generalized framework to evaluate the structural performance especially for typhoon landing whole process. This study utilizes the measured wind speeds of the strong typhoon "Hagupit" to establish a unified typhoon parametric model, during which the correlation of typhoon wind parameters including angle of attack (AoA), turbulence intensity, integral length scale and mean wind speed were taken into consideration. The measured typhoon process charactered with center-through effect with M-type average wind speed curve. Furthermore, the structural performance of long-span bridges with different spans from 1500 m to 2500 m main span was systematically studied. The aerodynamic parameters of the bridge deck section, including the aerostatic coefficients, flutter derivatives at different AoAs, and aerodynamic admittance under different oncoming flow conditions were identified through wind tunnel tests. Finally, the wind-induced buffeting performance was calculated by the buffeting frequency domain algorithm, showing various structural wind effect characteristics during the typhoon landing whole process. The maximal buffeting response is not necessarily related with the wind speed, and other wind characteristics especially turbulence intensity and AoA, etc. also affect on the results.