Temperature Effect on Main Girder of Strengthened Dongming Huanghe River Highway Bridge in Service

Abstract

Abstract The main girder of Dongming Huanghe River Highway Bridge was the first prestressed concrete (PC) continuous box girder bridge strengthened by a cable-stayed system in China. In order to study the temperature effect of the main girder structure of Dongming Huanghe River Highway Bridge after reinforcement, based on the measured data of middle span deflection, key section strain and typical crack width, the curve equations of strain and temperature of main girder were obtained by the regression analysis method. The results show that the annual strain value of main girder changed with the acquisition time in a sinusoidal function, and was linearly related to the temperature. The variation of mid-span deflection decreased gradually from side span to middle span, and varied dynamically with temperature in the whole girder, which also has obvious correlation with temperature. The crack width fluctuated up and down in a certain numerical range, which belonged to respiratory cracks and had equally correlation with temperature.