Temperature Effect Analysis Of Curved Continuous Rigid Frame Bridge Based On Measured Temperature Field

As the construction of highways in China continues to advance to the west,continuous rigid-frame bridges have become more and more cross-mountainous because of their comfortable driving,strong crossing ability,construction of superstructures not being disturbed by terrain and mature construction technology The first choice for the region.Among them,the curved continuous rigid frame bridge has the advantages of flexible and adjustable line shape,which can greatly reduce the length of the road exhibition line at the critical time.The complex and changeable climate in the western region will inevitably have a certain impact on the curved bridge,so it is very important to analyze the effect of temperature on the curved continuous rigid frame bridge.This article relies on a curvilinear continuous rigid frame bridge project under construction in Yunnan area.By embedding temperature sensors in the pier beams,the temperature field that fits the laws of the region is fitted,and the solid model of the full bridge is established using ANSYS to analyze the curved continuous rigid frame bridge The stress and deformation under the effect of sunshine temperature difference,find out the relevant laws,and provide suggestions and references for the design,construction and maintenance of the same bridge type in the area in the future.The main contents of this article are as follows:1.Consult relevant literature,briefly introduce the development history of continuous rigid frame bridges and the characteristics of curved continuous rigid frame bridges,and summarize the research status of temperature effects at home and abroad.2.List the classification and characteristics of temperature load,study the related theory of temperature load,and introduce three analysis methods of temperature load:Fourier heat conduction equation solution,approximate numerical analysis and semi-empirical semi-theoretical formula.By comparing and analyzing the relevant content of the temperature gradient in the domestic and foreign codes,the solution method for the temperature gradient in this paper is selected.3.Introduce the temperature sensor embedding scheme in the pier and beam.Screen the long-term observed temperature data of the main pier and main girder.Firstly,the temperature data of main pier and main girder observed for a long time are screened,and the most obvious temperature gradient is selected.Then select the simplified formula of temperature gradient by Liu Xingfa,and fit the temperature gradient function of main pier and main girder according to the principle of least square method.The most obvious temperature gradient curve along the wall thickness direction among the four faces of the main pier is:T_y=19.0e^-4.179y;The vertical temperature gradient curve on the top surface of the main beam is:T_y=19.8e^-4.874y.4.Firstly,the rationality of fitting the temperature gradient curve in this paper is verified by the stage analysis.Then,adopt large-scale general finite element software ANSYS to analyze the construction phase of the full bridge（the maximum cantilever phase and the side span closing phase）and the bridge completion phase.The following conclusions are drawn:The mid-span maximum cantilever at the side span closing stage is the most dangerous,and the displacement in the three directions of horizontal,vertical and vertical under the influence of the temperature field of the pier and beam is the largest;the nonlinear temperature gradient of the pier and beam will cause the structure Larger temperature stress,where larger tensile stress will have an adverse effect on the bridge span structure;bridge deck pavement will have a greater impact on the temperature effect of the structure;the measured temperature gradient is compared with the provisions of the Chinese Highway Code,It will produce greater deformation and internal force.In actual design and construction,comprehensive consideration should be given to the code and the climatic conditions at the site of the bridge site.