The Effect of Cold Waves on the Structural Performance of Concrete Box Girders

As the frequency of thermal extremes gradually increases owing to climate change, the role of thermal loads on bridge performance increasingly becomes a concern. The purpose of this study is to investigate the suitability of AASHTO Bridge Design Specifications in quantifying with confidence the design thermal gradients that account for cold wave events. An advanced finite element platform was used to model the thermal performance of a prestressed concrete box girder and to analyse the thermal gradients that occur during cold wave events. Meteorological data on four historical cold wave events in Ontario, Canada, were used as input in the thermal models to simulate the temperature distribution within the bridge deck. The temperature–time history distributions obtained were then used as boundary conditions in a structural finite element model to simulate the structural response. The thermal results indicate that the AASHTO recommended gradients failed to capture the true thermal load distribution within the superstructure, which led to an underestimation of the resulting structural implications.