Effect Of Cyclic Temperature Loading On The Prestressed Concrete Box Girder

Internal structural members of the concrete bridge that exposed to the natural environment exists the non-linear temperature field, the role of the temperature generated within the concrete stress and deformation direct impact on the reliability and durability of concrete structures.The concrete box girder, temperature effects are more significant. Many of the prestressed concrete box girder which is considered perfectly serious cracks due to temperature effects, some of the bridge even forced to outage and repair, causing serious economic losses.Take the research of temperature field, temperature effect and deformation properties on P.C box girder through artificially temperature increasing. According to the site collected temperature data, to arrive at the vertical temperature distribution of box girder model cross-section, the corresponding distribution function and the horizontal distribution of temperature, recording stress data simultaneously, to work out the corresponding temperature effect. According to the measured temperature field in the data set up finite element analysis model, analysis of temperature effects, and then the measured effect of temperature data and compared the results of the analysis, Confirmed box girder with a larger horizontal and vertical tensile stress.Take the repeated action in the temperature difference on P.C box girder through artificially repeated temperature increasing, research on influence of role of repeat solar temperature on mechanical deformation of prestressed concrete structures. In order to eliminate weight and other factors, do an I-beam experiment for comparison, research on the affect of deformation properties, and make comparative analysis with the experiment result of box girder. Set up finite element analysis model for simulation analysis, compared with the measured data, The results indicate that non-uniform shrinkage on the top and bottom plates of the prestressed concrete box girder would be induced due to the fluctuated nature temperatures, which would finally result in the downward deflection of the prestressed box girder.The research of temperature field, temperature effect and deformation properties have a significant guiding role in the design, construction and operations of box girder, and have great significance In the actual project.