The Study On Wind Load Internal Force And Buffeting Practical Calculation Of Continuous Rigid Bridges At Cantilever Construction Stage

The wind effecting on bridges become more prominent as the structures grow with longer span.And cantilever construction method is usually adopted in the long-span continuous rigid frame bridge construction.Turbulence wind often induces the bridges to the buffeting response at the longest cantilever construction stage and the great buffetings are bound to affect the construction safety,wind load always become the dominant load and must be fully considered during construction.But there are very few simplified formulations are used for estimating the response of buffeting on rigid frame bridge in this stage.Therefore,the research of this thesis has certain practical value and is significant in engineering project.The main contents of this thesis are included below:First,the parameters which affect the buffeting response at the longest cantilever construction stage are analyzed in details in terms of the method of buffeting response spectrum.The proportion of the buffeting background part to the total buffeting response is investigated carefully.The results indicate that the variations of wind velocity,damping and structural frequency play major roles in affecting the buffeting response,and the buffeting background part of response should not be ignored.Second,the internal force of the rigid frame bridge produced by static and turbulent winds respectively is calculated.The results indicate turbulent wind which effects on bridges should be calculated.Third,according to the requirement of practical engineering,the accurate analysis method based on the method of buffeting response spectrum is simplified with considering the effect of background response,and the simplified formula for engineering application of the bridge in the longest cantilever state is presented.Forth,the methods and results mentioned above are tested and verified by full aeroelastic model testing of an engineering example in a scale of 1:100.It shows that the response of buffeting on rigid frame bridge can be estimated by the simplified formulation.