Climate change intensifies bridge temperature: Evidence from 26 Years of monitoring data

Global warming has been increasing during the past decades and has been observed from worldwide observation stations. However, its impacts on civil infrastructure have not been observed or recorded due to a shortage of long-term field measurement data. This study uses the 2132-m long Tsing Ma Bridge in Hong Kong as a testbed and investigates the effects of climate change on the long-span bridge using 26 years (1999–2024) of field monitoring data. It shows that the annual mean temperature of the bridge deck has increased by 0.28°C per decade and the annual extreme temperatures have risen by 0.50°C per decade. Moreover, the annual 90th percentile bridge temperature and the frequency of extreme heat events exhibit an increasing trend. The standardized regression analysis shows that the ambient air temperature dominates the bridge temperature change. Finally, heat-transfer analysis is conducted to calculate the temperature distribution of the bridge. The numerical and monitoring results confirm the bridge temperature rise during the past decades. This study, for the first time, provides the real evidence of climate warming’s impacts on long-span bridges using 26 years of field monitoring data, the longest in the world. The results highlight the urgency of reducing greenhouse gas emissions and developing adaptation strategies to mitigate the effects of rising temperature on the safety and serviceability of infrastructure in a warming world.