Temperature Analysis of a Long-Span Suspension Bridge Based on Field Monitoring and Numerical Simulation

Structural temperature is an important form of loading for bridges, particularly for long-span steel structures. In this study, the temperature distribution of the Humber Bridge in the United Kingdom is investigated using numerical simulation and field measurements. A two-dimensional fine finite-element model of a typical section of the box girder of this long-span suspension bridge is constructed. The time-dependent thermal boundary conditions are determined using field meteorological measurements with external surface heat-convection coefficients varying according to differing local wind speeds they experience. Preanalysis is adopted to determine the initial thermal condition of the model, then transient heat-transfer analysis is performed and the time-dependent temperature distribution of the bridge is obtained, leading to numerical temperature data at different locations in different times that are in good agreement with the measured counterparts. The vertical and transversal temperature differences (TTDs) of the box girder are also investigated. Both measured and numerical results show that the transversal temperature variation across the streamlined girder is significant. The effects of the box-girder shape, pavement of the upper webs, and bridge orientation on the TTD are finally investigated.