Study On Wind Load Determination For Xiangluowan Bascule Bridge On Hai-river

Wind load on bridge structure is generally determined according to General Codefor Design of Highway Bridges and Culverts. However, for bascule bridge, the shapeof the bridge varied during the open-close procedure. Meanwhile, wind load act onlarger area of the bridge and the structure stiffness is smaller than closed bridge. Thewind induced vibration is relatively large. In this paper, Xiangluowan bascule bridgeon Hai-river was taken as a case study, body coefficient and wind induced vibrationcoefficient were determined to enable the wind load calculation for the design of thebascule bridge. The research work includes:(1) Wind pressure coefficient was determined for bascule bridge at differentpositions during the open-close procedure by numerical wind tunnel method. Bodycoefficients were then calculated from the wind pressure coefficient respectivelybased on equivalent force and equivalent moment caused by the wind.(2) Wind induced vibration coefficient was studied with time domain method.Wind speed history was first simulated by FFT update harmony superposition method.Then the dynamic behaviour of the opened bascule bridge under the wind load wasstudied by time history analysis. At last, the wind induced vibration coefficient wasdetermined by comparing the static and dynamic behaviour of the bridge structureunder wind load. The results showed that wind induced vibration coefficientcalculated based on displacements, stresses and reaction forces agree very well and donot vary during the open-close procedure.