Effect Of Structural Parameters Between Split Boxes On Wind Resistance Of Split Three-box Girders

With the rapid development of China’s economic construction,large-scale infrastructure construction has been carried out in recent years,and a large number of long-span highway and railway bridges have been built in the eastern and coastal areas.Because of its stronger spanning ability,long-span bridges have been widely used in the eastern and coastal areas,such as the Xigumen Bridge,the fourth Nanjing Yangtze River Bridge and the Shanghai Yangtze River Bridge.The main spans of the typical long-span bridges are all more than 1000 meters.These long-span bridges not only have huge investment and long construction period,but also are of great significance in economic development and national defense construction.once they are destroyed,they will have a great impact on the traffic and economy of the whole region,so their safety is very important.However,due to the large span and flexibility of long-span bridges,it is easy to lose stability under the action of static wind.Therefore,the wind resistance of long-span bridges is the most important.Therefore,this paper will study the wind resistance characteristics of the split three-box girder by the combination of wind tunnel test and numerical simulation,combined with the cross-section form of "three-box separation".The main research contents include:The main contents are as follows:(1)the general situation of the project and the method,model design and measurement technology of measuring bridge static three-component force in wind tunnel test are introduced,and the static three-component force data of bridge state and construction state are obtained.(2)two-dimensional numerical models of bridge state and construction state are established,and the static three-component coefficients of bridge state and construction state of the two-dimensional numerical model are calculated,and the experimental results are compared with them to verify the rationality of the numerical model.(3)the numerical models of different slotting width and height difference between boxes are established,and combined with the section form of "three-box separation" main beam,the effects of different slotting width and height difference between boxes on the static three-component force of the main beam are studied.The changing trend of the slotting width to the static three-component force of the split three-box beam is obtained.(4)the measuring points are arranged for the numerical model of main girder with different slotting width and height difference between boxes,and the influence of different slotting width and height difference between boxes on the average pressure of split three-box girder is studied.The variation trend of the slotting width to the average pressure of the split three-box girder is obtained.