Research On Temperature Effect Of Long-span Steel Box Tied Arch Bridge

Since the 1960s, a series of studies on the temperature effect in bridge structure has been done by the bridge experts and researchers all over the world, the computational theory of Bridges temperature effect is better than Previous. However, the research of temperature effects was mostly focused on the concrete bridge structure, while the research of steel box arch bridge was relatively small. Therefore, to make the further and meticulous research for the temperature effects on steel arch bridge is necessary and meaningful. Taking a bridge in Passenger Special Line from Chengdu to Guiyang as a project background, the temperature stress and displacement of the steel box arch bridge are studied in this thesis.Through consulting a large number of reference materials, the current status in temperature research about steel box arch bridge and the definitions of temperature load in Bridge Codes are summarized, and the related theory about temperature effect three commonly used method of analyzing temperature field and calculation method of bridge temperature effect are introduced in this thesis.By building up entire bridge model in Midas/Civil and choosing proper temperature from current Codes and Specification, the temperature effect of steel box tied arch bridge is analyzed in this thesis. This temperature includes four aspects, the first one is temperature gradient of steel box girder, the second one is temperature gradient of piles and columns, and the third one is the whole rising and falling bridge temperature, the other one is the difference temperature between the pier and other components. Results indicate that tensional stress of steel beam in railway deck is noticeable under temperature loading. While Piers and columns are subjected to temperature, temperature caused stress are influenced by direction of sunshine and displacement is influenced by height of themselves. Overall variation of temperature has little influence on super- structure, whereas, it has bigger influence on piles and columns. Also, the temperature of gradient for girder, arch, cable, and pier has little influence on structure. These results accomplished in this thesis can provide necessary reference for construction and design; further give useful suggestion to Codes.