Research And Prediction On Temperature Effect Of Long-Span Steel Box Tied Arch Bridge

As concrete bridge structure is easy to crack and other reasons, making domestic and foreign scholars studyed Temperature effects on concrete bridges more in the past few years time, but less research on the steel box girder. In recent years, with the steel box girder applied more widely, people found that temperature effects on the whole steel box girder structure is relatively large during the construction, has become an important factor affecting the quality of the construction of large-span steel box girder structure.Countries and each countrys’ design specifications on steel box girder temperature gradient are inconsistent. regulation of the temperature gradient in the bridge is not suitable for steel box girder. It is necessary to study the temperature effect on steel box girder.In this paper,on the base of the Guangzhou Nansha District Phoenix Bridge engineering, choose a representative weather, and measure for a period of 24 hours on Phoenix Bridge steel box girder temperature field. Using segmentation functions fitting curve the steel box girder roof and floor changed temperature that it can get the characteristic of the changed temperature field and temperature gradient mode of the Nansha District Phoenix Steel Girder Bridge individual components.Using Exponential function of the Phoenix Bridge steel box girder most adverse temperature differential curve obtained by fitting the vertical temperature difference curve mode which is suitable for subtropical regions of the steel box girder. Using the finite element software ANSYS solving steel box girder temperature field by numerical that get solution of transient temperature field obtained in different parts of steel box girder caused by changes in the natural environment, the calculation results are consistent with the experimental results, indicating that the boundary conditions and the temperature field model of this article are select reasonable,then through the theoretical model study the temperature field sensitivity of various environmental parameters and structural parameters. Sensitivity control parameters derived factor absorption greatest impact on the temperature field calculation, wind speed, followed by radiation rate with minimal impact. In this paper, the temperature gradient mode with the overall heating and cooling conditions, the establishment of a full-bridge model by MIDAS.civil software, steel box girder calculate the temperature effect, found that the temperature stress generated by temperature effects, temperature deformation can not be ignored.In this paper, BP neural network and cable force Kriging model different construction temperature correction separately predict good agreement with the measured contrast, higher kriging model prediction accuracy. At different temperatures of the Phoenix Bridge Construction Hanger Force values fluctuate is relatively small.