Estimating Extreme Thermal Loads in Composite Bridge using Long-term Measured Data

The purpose of this paper is to provide realistic values of extreme thermal loads applicable to composite box girder bridges on the basis of the statistical analysis of long-term measured temperature data. For this purpose, temperatures were recorded at a newly constructed composite box girder bridge for about 6 years. Before analyzing the extreme values, major thermal loading parameters that characterize the temperature profile are defined. The limit distributions of the thermal loading parameters are then determined by the tail-equivalence method, and the thermal loading parameters corresponding to selected return periods are calculated. Finally, the results are compared to the specifications suggested in a current design code for thermal loads.