Study On The Box Girder Temperature Field Of Sunlight And Impact In Beijing

Bridges exposed to the natural environment,influenced by the factors such as solar radiation,environment temperature,bridge temperature field is changing all the time.China's vast,environment and climate differ in different regional,highway bridge design general specification specified temperature field cannot cover each region.Therefore,this paper studies on box girder temperature field of sunlight in the Beijing area,explore the box girder temperature field distribution and its effect on box girder stress state.No.1 Monitor of box girder temperature fieldThrough the long-term monitoring of temperature field of box girder bridge,on the one hand,study on the variation of temperature field of box girder structure in a day;on the other hand,explore the form of curve of box girder temperature field distribution.In the period from January 2015 to December 2015,under the condition of clear cloudless,monitoring of the longitudinal and transverse gradient temperature of the box girder,and set up a database of the concrete box girder?steel box girder temperature field,to lay the foundation for simulating the temperature gradient curve.No.2 The theoretical calculation of the temperature fieldBased on solar radiation and the theory of heat conduction,establish the boundary conditions of box girder temperature field in sunlight.Determine the physical with the structure of thermal conductivity,solar radiation,the correlation coefficient of convective heat and the theory of heat conduction.By using ABAQUS finite element analysis method simulating the change of temperature field of structure under different azimuth.No.3 The determination of the form of gradient temperature curveFit vertical,horizontal gradient of temperature of concrete box girder and the steel composite box girder by monitoring data of temperature field.Under the conditions that the correlation coefficient and confidence probability meet,determine the maximum temperature difference curve form of two bridge,can provide reference for the future standard revision.No.4 Analysis effect of box girder temperatureEstablish finite element model of concrete box girder and the steel composite box girder,By loading the specification and the measured temperature gradient,study the stress state of the concrete box girder and the steel composite box girder under two kinds of temperature gradient and explore the effect to the box girder stress by vertical temperature gradient and the effects of box girder stress state by transverse gradient temperature.