Typhoon Measurement And Buffeting Response Analysis Of Long-Span Arch Bridge

In the past 30 years,large-span arch bridges have been widely used in infrastructure construction in China.For example,Wushan Yangtze River Bridge,Caiyuanba Yangtze River Bridge and Guangzhou Xinguang Bridge are arch bridges spanning more than 400 meters.The development trend of large-span and light-weight modern arch bridges has led more and more experts,scholars and arch bridge designers to pay attention to the study of wind-resistance of long-span arch bridges.The analysis of bridge buffeting is one of the important research topics.At present,the buffeting time domain analysis of long-span arch bridges under typhoon is mostly based on the objective power spectrum function to artificially simulate the spatial pulsating wind field,and then obtain the wind speed and direction data,and then pass the segment model test or CFD technology to the structural section.The three-component force coefficient is identified to calculate the static wind,buffeting force and self-excitation of the bridge.Finally,the time-domain response of the bridge under the action of the typhoon is obtained by the method of solving the dynamic finite element.However,due to the strong regionality of the typhoon,the empirical power spectrum cannot fully reflect the typhoon characteristics under real conditions.Therefore,obtaining the actual and reliable typhoon measured data at the bridge site and using it for the entire analysis process will have the primary and important significance for finally obtaining the true structural buffeting response.According to the wind speed data of Typhoon Soudelor recorded by the array of wind towers in Dadeng Island,Xiang'an District,Xiamen,the time history of the bridge's buffeting force is calculated,and the transient analysis function of finite element software ANSYS is used to calculate the Wuyuanwan Bridge of Xiamen.The buffeting response of the bridge at different moments of the typhoon.Firstly,combined with the on-site measurement work of Typhoon Soudelor,the wind speed data recorded by the wind tower array is processed by MATLAB programming software to analyze the pulsation characteristics of the typhoon,such as turbulence,turbulent integral scale,and pulsating wind power spectrum.And spatial correlation and so on.Secondly,using the computational fluid dynamics(CFD)technique,the static three-component coefficient of the main beam and the rib of the Wuyuanwan Bridge is obtained.Finally,the finite element model is established,and the static wind load and the chattering force of the Wuyuanwan Bridge are determined based on the measured wind speed data and the static three-component force coefficient.The transient analysis of the finite element software ANSYS is carried out by the solution method of the dynamic finite element method.The function performs time domain analysis to obtain the time-course response of the bridge at different moments of the typhoon.The research work of this paper is based on the measured typhoon data at the bridge site.As a special wind field with strong regionality,the chattering response can be calculated by obtaining the measured data,which can be regarded as the traditional simulated space pulsating wind field.An improvement from the "source" of the chattering response is then calculated to improve the accuracy of the analysis.