Field monitoring and numerical analysis of Tsing Ma suspension bridge temperature behavior

It is important to take into account the effect of temperature in assessing the structural condition of bridges. However, very few quantitative studies have examined the temperature behavior of large-scale bridges because of their large size and complicated configuration. This paper, for the first time, investigates the temperature distribution and associated responses of a long-span suspension bridge - the 2132-m-long Tsing Ma Bridge - through a combination of numerical analysis and field monitoring. With appropriate assumptions, fine finite element models of a deck plate, section frame, and bridge tower are constructed to facilitate thermal analysis. With ambient temperature measurements and a solar radiation model, the time-dependent temperature distribution within each of these components is calculated through transient heat transfer analysis. The numerical results are verified by comparing them with field monitoring data on temperature distribution and variation at different times and in different seasons. The temperature data are then input into the structural model of the whole bridge to obtain the displacement and strain responses of various bridge components, with a good level of agreement being achieved between the bridge responses and the monitoring data. This exercise verifies both the accuracy of the analytical method employed and the effectiveness of the monitoring system installed on the bridge. The study shows that integrating numerical analysis with field monitoring data provides for a thorough understanding of the temperature behavior of long-span bridges.