Analysis of Measured Temperature Field of Unpaved Steel Box Girder

This work used the measured data during the whole test period to study the law of temperature change in the steel rail beams, and the distribution characteristics of the sunshine temperature field, in straddle-type monorail tourist transportation systems, employing a field-test and a numerical simulation. The curve form of the temperature gradient was determined by a comparative analysis of the existing domestic and foreign norms. Finally, the generalized extreme value distribution model was used to predict the extreme value of the representative value of the temperature difference, and the value of the temperature base, for different return periods, and the complete temperature gradient model were determined. Results: During the whole test period, the maximum vertical positive temperature difference of the steel box girder was 15.21 °C, and the negative temperature difference was −5.07 °C. In addition, the effect of the ambient temperature, considering solar radiation, was found to be an important factor affecting the distribution of the vertical temperature difference. The analysis determined that the positive and negative temperature difference curves in the unpaved steel box girder were multi-segment polylines and linear straight lines, respectively. The extreme value predicts that the representative temperature differences between T1 and T2 of the 450 mm beam during the 50-year return period were 17.2 °C and 4.58 °C, respectively, and T1 and T2 under the 100-year return period were 17.38 °C and 4.62 °C, respectively.