| When large-span pre-stressed concrete rigid frame bridge structures are subjected to temperature load, large internal force will across within the structure, and which will weaken the resist-cracking performance of its section and temperature cracks can be produced. Thus the safety and the durability of the bridges may be seriously affected. The work based on the former researches, taking a typical three-span pre-stressed concrete rigid frame bridge as the background, the influence of the temperature load on the bridge structure is analyzed.Based on the heat and the FEM theory, the influence of temperature load and the hydration heat as well as its distribution on this type of bridges is researched, and analysis by adopting different models of temperature load in the cores of various countries. The result show that for pre-stressed concrete continuous frame bridges, the results obtained by calculating modal in Chinese national code"General Code for design of Highway Bridges and Culverts"(JTG D60-2004) is more reasonable; fairly large tensile stress will arose at the bottom of the girder because of temperature increasing, and it is even larger than the effects of live loads sometimes. 3d after finishing pouring concrete, temperature increasing by the effect of hydration heat will reach maximum, and there is large temperature differences between box girder wing plate and roof. Also the large temperature stress at the cantilever flanges must pay great attention.Large span rigid frame bridge construction monitoring work needed to control the conversion of stress and strain appropriately. It's very difficult to using accurate method for the analysis of the stain, which is influenced by complex factors. In this paper, we use the method of combining the values calculated and measured to deal with the conversion problems of stress and strain, get better results, the calculation is simple and easy to promote. |
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