Study On Temperature Field And Its Effect Of Long-Span Concrete Box-Girder Bridge

With its excellent section characters, the prestressed concrete box girder plays a main role in PC bridges. During the bridge design and construction, the influence of temperature needs to be considered. However, the related specifications or standards are dissimilar in different criterions or countries. The dissimilarity is resulted from the variables of the exposure environments, material property and so on. So the specifications can only be used as reference.Based on the Honghai Bridge construction monitoring work, the temperature field and the strain field of the box girder are measured on site by the simultaneous testing of "Time-Temperature-Stress". The bridge is a PC continuous box girder bridge. Based on the temperature data measured on site, the thesis brings forward the characters of the temperature field and the fitted vertical and transverse temperature gradient of PC continuous box girder bridge, adopting a shape of temperature gradient used in the Chinese railway standard and the New Zealand standard. According to the measured data, the effect of PC continuous box girder bridge subjected to temperature is then analysed. The temperature field and temperature effect are also simulated by the finite element software ANSYS according to the parameters collected on site. Thus, the characters of the temperature field and the fitted temperature gradient are proved to be available. And the accuracy of the temperature field characters and the measured temperature effect data is satisfactory. In succession, the error between calculated value and measured value is analyzed and the reasons are also explored by comparation. At last, the thesis modifies the concrete stress which is influenced by temperature gradient in construction monitoring according to theoretical analysis and the data measured on site.