Thermal Effects Analysis For Concrete Continuous Bridge With Application

Nonlinear temperature distribution in box girder cross-section under the influence of factors such as solar radiation and temperature changes will lead to temperature stress and displacement of the girder. Temperature stress can be the size of the stress of externally applied pipe load, even the temperature effect of concrete box girder will directly affect the safety of the concrete box girder bridge. The temperature has become one of the reasons for damage to the concrete bridge, especially in the concrete box-girder bridge. However, temperature effect is quite complex, and the existing codes for design is still not perfect.. In the design of concrete bridge, unified model usually causes great errors of stress and the deformation of temperature. This paper is aimed at the concrete railway bridge box-girder thermal analysis, which base on the observation data so that improve the concrete box girder temperature field of the theory and method of railway Bridges. The main research contents are as follows:(1) Base on the solar physics, heat transfer and related theory, this paper investigate the factors of affecting the temperature distribution in concrete box girder bridge so that sun radiation intensity formula of box girder in vertical and horizontal can be derived, the vertical temperature gradient of concrete box girder cross-section pattern to carry on the theoretical derivation, and then different method of temperature stress which based on vertical temperature gradient mode in cross section are analyzed and compared.(2) The box girder cross section of the vertical temperature gradient reference mode is carried out through Temperature variation analysis in Box girder beam lateral roof, concrete box girder roof vertical, lateral and Base plate and data are fitting to the experimental findings for a period of time on Box girder. Temperature impact can not be ignored which can get results from temperature stress and deflection from simulation model of the bridge rooting on on the vertical temperature gradient mode. And the calculated results and the results under the specified section temperature gradient mode are compared. Existing similarity between various of temperature gradient mode can be validated by Linearity theory.(3) Modified model to vertical temperature gradient mode which vertical temperature gradient mode in this paper was revised on existing Chinese railway specifications were proposed and validated. Prestressing camber calculation under the temperature effect can be used to guide and provide reference for the practical engineering design and Construction control. Lastly, Folded across the reasonable temperature range of closed are calculated by using impact analysis of differences in temperature effect.