Analysis Of Sunshine Thermal Self-restrained Stress In Separate Concrete Box Girder

In the existing Code for design of highway bridges and culverts in China, the two components of sunshine temperature gradient are refer to the code for the United States, and converge to a single differential base in the whole country. This paper is based on the theory of solar radiation, take the analysis of separate concrete box girder bridge’s sunshine temperature field distribution and temperature load effect, aim of study the Hunan central area east to west bridge’s sunshine temperature load effect characteristics, provide a reference for improving the Code for design of highway bridges and culverts.In this paper, take a east to west’s arch’s separate concrete box girder cable-stayed arch bridge as engineering background, in the absence of bridge measured intensity of solar radiation, according to the theory of solar radiation, back-calculate the intensity of solar radiation, determine the temperature gradient of the bridge.Take ANSYS finite element software as working platforms, established the three-dimensional temperature field’s analysis model, take the temperature field simulation analysis of the separate concrete box girder, the analysis’s results show that, the outer surface’s temperature variation of concrete box girder is equal to atmospheric temperature variation, take the temperature’s time-history analysis on X1beam’s roof, bottom, web’s key point, get the corresponding variation of temperature, meanwhile, take the transverse temperature difference analysis of roof, bottom, outer web and inner web and vertical temperature difference in beam depth direction,get the corresponding temperature difference value, and fitting corresponding temperature gradient.Take ANSYS finite element software as working platforms, established the separate concrete box girder’s three-dimensional space model, according to the temperature field analysis’s temperature loads result, take advantage of indirect coupling function of ANSYS, take the analysis of self-restrained stress in this separate concrete box girder caused by sunshine, the results show that, in the14:00when exert biggest vertical temperature difference, the inner surface of the roof’s transverse tensile stress values is3.38Mpa, the outer surface of the roof’s maximum horizontal compressive stress is-3.6Mpa, the inner surface of the web appear vertical tensile stress, the biggest value is0.95Mpa. meanwhile, choose some different paths, take the analysis of variation law of temperature stress in horizontal and vertical stress of the internal and external surface of the upperstream and downstream’s roof, outer surface of the bottom, the lateral surface of the web in beam depth direction.