Study For Temperature Field And Temperature Effect Of PC Continuous Box-Girder Bridge

With the effort of solar radiation, PC continuous box-girder bridge structure will have a non-linear temperature field and a great temperature stress, it is possible to structure cracks, which has seriously affected the structure of security and durability. We must consider the influences during the design and construction.Based on the extensive research, information at home and abroad, the paper introduces the reseach of the effects of temperature, and in detailed introduction world some main national norm. Introduce finite difference method and finite element method and the effects of temperature calculation method of concrete box -girder temperature field.According to Daqinggou PC continuous box-girder bridge of Yongcheng city Henan province, the paper uses continuous observation method to observe temperature field in several month. According to the data, the paper detailedly analyzes the change regularity for temperature field in each concrete box-girder components in solar radiation and the air humidity influnence of temperature gradient. this paper also precedes the regression analysis to get the Fitting's temperature gradient function.Building ANSYS model uses the Fitting's temperature gradient and the temperature gradient which defined by the norm(JTG D60-2004).Based on the results of the model, we know that the most unfavorable position of three-span prestressed concrete continuous box-girder is located at the bottom of top plate of mid-section in the middle span. We also know that the results of the Fitting's temperature gradient analysis is bigger than the norm's, the norm's is non-safe. Under the vertical temperature gradient, PC continuous box-girder bridge not only has the longitudinal temperature stress, but also can have the crosswise temperature stress, the two are in the identical magnitude basically. Finally, the paper detailedly introduces the measures which the designer used to induce the temperature deformations of the bridge structure. A reference is provided for studing on the temperature observation and the temperature gradient of the similar profiled bridge.