Temperature gradient zoning of steel beams without paving layers in China

The solar temperature field and its temperature effects on the straddle monorail tourist transportation system (SMTTS) significantly affect its mechanical performance. To investigate the distribution law of the daylight temperature field of the unpaved steel beams, the daylight temperature fields of box-type and I-sectional steel beams in different regions were measured and simulated. With the simulation results, the vertical temperature gradient curves of the unpaved steel girders were determined. Afterward, with the historical meteorological data as variables, the parameters of the extreme value model of generalized extreme value (GEV) distribution were obtained, and the representative values of temperature differences in China, based on the recurrence period, were analyzed. By analyzing the temperature difference values in 34 cities in China, an empirical prediction formula for the representative temperature difference value with three parameters was proposed, and the temperature gradient partition was established. The results indicated that the vertical temperature gradients of closed-section steel box girders are about 2–3 °C greater than that of open-section I-beams. Moreover, there are apparent geographical differences in the temperature difference values of steel girders.