Research On Temperature Field And Temperature Effect Of Half-through Tied Arch Bridge With Steel Box Arch-ribs

Along with the rapid development of bridge construction in our country, the long span steel bridge has become a new development trend for its lighter-weight steel components and shorter construction period. Because of the good thermal conductivities of steel, most sensitive to the temperature changes, the steel bridge is significantly influenced by ambient temperature changes. At present, the design codes regarding temperature gradient of steel bridge vary from country to country. Under the circumstances, the research on the temperature field and temperature effect of the steel bridge is particularly urgent. Thus, the thesis analyzed on the most typical temperature field data which was observed on one half-through tied arch bridge with steel box arch-ribs, a long-span steel bridge in Zhejiang province, and studied its temperature effect by finite element software MIDAS/civil. The main work and conclusions are summarized as follows:(1) The thesis introduces the analysis theory of temperature field in bridge structure, classification of temperature effect and the theory of temperature effect computation in details. Then specifications for temperature effect in national and international design codes are introduced.(2) With the temperature distribution analysis based on the measured temperature data of stiffening girder, a vertical temperature gradient curve is obtained after flitting the unfavorable vertical temperature distribution by piecewise function. It's a valuable reference for future research on the temperature gradient of steel box girder.(3) The law of temperature distribution is derived through the analysis on the measured temperature data of steel arch ribs., After the fitting of its unfavorable temperature distribution using the numerical analysis software Origin8.0, the curves of temperature gradient along the vertical and transverse section are obtained.(4) According to the derived temperature gradient curve of the stiffening girder and steel box arch rib, nonlinear temperature gradient is equivalent to the linear temperature gradient. Using the finite element software MIDAS/civil to establish the overall bridge model, the temperature gradient effect and the integral temperature effect are calculated respectively. The result indicates that the thermal stress and temperature deformation produced by the temperature gradient and the integral temperature effect can not be neglected.