Research On The Temperature Effect And The Shrinkage And Creep Effect Of Prestressed Concrete Box Girder

Bridge structure works in the complex environment, its loading conditions is controlled bythe internal and external factors in the construction and operation process.In the prestressedconcrete box girders structure, the temperature effect and shrinkage creep effect of prestressedconcrete box girder cannot be neglected. Especially for statically indeterminate system, Thetemperature cracks produced by temperature is easy to be found, which affect the practicalityand durability of structure. Shrinkage and creep effect also has a very significant influence tothe practicality of prestressed concrete box girder.In this paper, the Liutiao river bridge located in Yongdeng-Gulang highway, as a testbackground, the environment parameter and box girder temperature of which has beenobserved for one year. The regularities of temperature process curve change of box girdersection and the temperature distribution of box girder section has been analysed by fourseasons, the fall, winter, spring and summer. With which compared the environmentaltemperature.It summarized the regularities of changes and distribution of the concrete boxgirder temperature.The temperature distribution of concrete box girders is space distribution.Temperature not only exists along the vertical section of box-girder temperature, but alsoalong the longitudinal girder and level certain temperature difference exists. To master theregularities of the changes and distribution of the concrete box girder temperature can beapplied to estimate the temperature of box girder roughly according to environmenttemperature in the period of bridge construction.Based on the environmental parameters and material parameters of the bridge, a3D boxgirder finite element model has been set up, the temperature of box girder are calculated andcompared with the measured value.Utilized the analysis results of concrete box girdertemperature, the temperature-structure coupling effect are calculated. Based on the calculatingof finite element model, the structure reaction of prestressed concrete box girder structureunder dead weight load and the load caused by weight and temperature are analyzed by theway of comparison, and the regularities of distribution along the longitudinal and horizontalbridge of longitudinal temperature stress and transverse temperature stress also analyzed.It introduces the prediction model of concrete shrinkage and creep usually used incalculation,The reaction of box girder under the dead weight load and temperature load arecalculated with the finite element calculation software, which cosidered shrinkage and creep effect,and the regularities of the change and distribution of the stress and strain produced bydead weight or temperature are also analyzed,and a comparative analysis on structurereaction between which is done.Through the analysis of the above aspects, the role of the temperature effect and shrinkagecreep effect of prestressed concrete box girders are summarized, and put forward some furtherstudy of the problems and possible method of solutions.