Distribution And Calculation Mode Of High-speed Railway Box Girder Bridge Sunshine Temperature Field

The concrete bridges of high-speed railway expose in the air for the long term, and these different enviroments result the different solar radiation and temperature around. The temperature change and the effect of solar radiation lead nonlinear thermal gradients, thermal stress and thermal displacement. As one of the most important factors that lead to the cracks in bridges during construction or service periods. Different temperature thermal stress calculated by the model varies within a certain range; it has significant influences on prestressed steel, smooth of bridge and ballastless track. So it is necessary to study the thermal gradients of the concrete bridges and the effect of temperature, to better guide the actual design.The temperature effects of the concrete bridges of high-speed railway were attributed to three categories in this paper, including materials, climate and special factors, and based on solar physics, general astronomy, meteorological science, heat exchange theory, slab track and mathematic methods, the Principle of heat exchange was researched between the structure and the external environment, and the model was make up by the structure of bridge and track system. Heat boundary conditions were built to act on the bridge section completely. While, using the software called ANSYS as a platform for the heat analysis of the high-speed railway bridge's box section. Different slab track caused the different distribution of temperature. And using software called MATLAB to make curve fitting. The parameters of influence on the the temperature distribution of high-speed railway'bridges were studied comprehensively. This paper summarized the specifications for the thermal gradients and the method of temperature effect all over the world, and analyzed, compared. At last, the stress and secondary stress of thermal gradients is calculated and analyzed to verify the security of bridge design and table a proposal for bridge's solartemperature design under considering the impact of track.