The Research On Sunshine Temperature Effect Of Long-span Continuous Rigid Frame Bridge

Temperature effect of concrete structures in civil engineering problem is a common problem.Theoretical and experimental studies have shown that the effect of thermal load generated in the bridge structure is usually higher than dead load,live load is more obvious,leading to destruction of the bridge structure,even one of the main reason of crack.In-depth research on the temperature effect of the concrete bridge structure in the atmospheric environment,has become an urgent problems to the academic circles and the engineering circles of bridge.Although the bridge design specifications of China and other countries give corresponding provisions about temperature gradient,subject to various factors,leading to the temperature gradient does not have the generality,study the problem of temperature effects only can reference but not copy the temperature gradient mode,it is necessary to further study the temperature effect.In this paper,based on existing research results,Guizhou to Sichuan Expressway cold River Bridge as project background,mainly for the following studies:(1)Through access to a large number of references,the paper described the formation,characteristics and influencing factors of temperature field of sunshine;describes the temperature distribution theory of concrete bridge structure,study the main factors of the temperature distribution of sunshine;introduced the role of heat exchange of the concrete bridge structure,characteristics and calculation methods of temperature effect.(2)Based on the measured data,obtained the temperature distribution law of box girder,according to the measured data were fitted by numerical analysis software for the bridge where the regional temperature gradient mode,and use large-scale finite element analysis software ANSYS,analysis the temperature field of sunshine of box girder during construction period by three-dimensional simulation,the simulation results were compared with the measured data to verify the accuracy of the temperature gradient mode . Meanwhile , calculated the temperature stress and deformation of box girder under sunshine temperature effect.(3)According to the sunshine temperature effect theory of pier and the finite element theory,use finite element analysis software ANSYS,based on the current bridge design specifications,were calculated the temperature stress of main sections and the displacement values of the pier top under three solar radiation conditions during construction period.