Study On Temperature Effect Of Prestressed Concrete Composite Box Girder With Corrugated Steel Webs In Extreme Temperature

The prestressed concrete composite box girder with corrugated steel webs which,has the novel structure form,the unique force performance and the beautiful external form,has been widely applied.Until now,researchers has focused on the mechanical behavior of the bridge,yet few has been done on the temperature effect although the temperature effect may be significant.In this paper,the temperature effect of prestressed concrete composite box girder with corrugated steel webs is studied based on the research of Xi Xian highway pedestrian bridge and Yusheng Yellow River Bridge.The main work and onclusions are summarized as followings:1)This paper introduces the research status of temperature effect on bridges and the regulations about temperature in the bridge design specifications at home and abroad.2)Based on the actual temperature of Xi-Xian Highway pedestrian overpass and Yesheng Yellow River Major Bridge,this paper analyzed the temperature field and deduced the temperature distribution of prestressed concrete composite box girder with corrugated steel webs.At the vertical direction of the box girder:for bridges with a small height of box girder,the web has the same temperature distribution across different vertical location in the sunshine.For bridges with a high box girder,an obvious curve distribution is stated along the vertical direction.Regardless of the height of the bridge,the temperature at the web is higher than the temperature of the top and bottom plat,and the temperature at sun side is higher than the back sun side.At the transverse direction of the box girder:the transverse temperature differences are small and don’t need special considerations.For beams with a concrete section,the temperature of the concrete parts is lower than the temperature of the steel web.But the temperature distribution along vertical direction is similar.3)Based on the theoretical study of the temperature field under the influence of sunshine,the initial state and boundary conditions of the structure are obtained.then through the large-scale finite element program MIDAS FEA,the Box girder section temperature effect of the Ye Sheng Huang River Bridge section id analyzed.The results show that the finite element calculation results are in good agreement with the measured values,and the temperature variation of the box section under sunshine can be simulated accurately.4)In this paper,we use the mathematical statistics to calculate the atmospheric temperature representative value of the Ye Sheng Huang River Bridge area at day and night,which under the extreme temperature condition,and then obtain the design temperature gradient distribution pattern of corrugated steel web by numerical simulation.Finally,the paper proposed temperature gradient of PC composite bridge with corrugated steel web which applied to the extreme temperature region of the northwest,and the mechanical effects of the temperature gradient are analyzed.