| Temperature influence is one important problem on bridge design. This article based on the equilibrium theoretics of heat exchange on box girder surface and the consideration of thermal instantaneous analysis method which is developed to calculate the stress field under different temperatures. By the methods upwards, the temperature field and effect of box girder bridge with corrugated steel webs and wide-flat irregular box girder bridge are calculated. On the basis of two kinds of special bridge structures, in-depth research has been carried out on the following aspects.This article takes the bridge across Yong Xin River of NingBo and ShiQiao interchange of Hangzhou as the research background. Adopting three dimensional finite element method which is used to analyze the change of bridge's temperature field in July, analyze the characteristic of temperature distribution in the top plate, base plate, flange plate, webs at different time as well as the temperature chang of various plates' outside surface, central surface and inside surface. Then it computed and analyzed the characteristic of temperature distribution in typical sections at 4:00 with the biggest negative temperature difference and at 15:00 with the biggest positive temperature difference.The history of daily temperature effect was computed by introducing the temperature field value of the whole model. This article picked up the historical change of temperature effect at various depths in the top plate, base plate, flange plate, webs which built up the box girder. At the same time, it analyzed the distribution of temperature stress and the lateral deformation of the corrugated steel web in the box girder bridge with corrugated steel web and analyzed the characteristic of the temperature stress' distribution of the lane in the wide-flat irregular box girder bridge. The results shows that: box girder bridge with corrugated steel web and wide-flat irregular box girder bridge under solar radicalization will rise strong cross and vertical stress at 4:00 and 15:00, which will cause certain main tensile stress in structure. So the designer should pay attention to the response of temperature effect in order to protect the concrete from cracking in design.In addition, this article compared and analyzed the computing results of the beam theory with canonical temperature gradient and the computing results of finite element method. In the end, the existent problem caused by adopting beam method to simulate the temperature effect was discussed. |
