Impact of Climate Change on the Thermal Behavior of Long-Span Suspension Bridges

Climate change can alter environmental parameters such as air temperature, wind speed, and solar radiation, potentially leading to rising bridge temperatures and imposing additional thermal loads. This issue is not limited to specific regions or bridge types but poses a global challenge to bridges in all regions of all kinds. With the acceleration of global climate change, bridges worldwide face rising temperatures and related impacts, and therefore, evaluating their thermal performance under a future climate is critical. This study is the first to apply downscaled climate data to assess climate change impacts on bridges, specifically predicting future bridge effective temperatures and the associated displacements. Using the Tsing Ma Bridge as a case study, 22 global climate models (GCMs) under medium (SSP2-4.5) and very high (SSP5-8.5) emission scenarios with heat-transfer analysis are integrated to predict bridge effective temperatures. The results show that the predicted bridge effective temperatures will reach 45.84°C and 47.13°C by the year 2100, respectively. The effective temperature is expected to rise further to 46.37°C and 47.93°C by 2117, exceeding the design temperature value of 46.0°C by 2105 under SSP2-4.5 and 2065 under SSP5-8.5. Temperature-induced displacements are also expected to increase significantly. By 2100, vertical displacements are projected to increase by 24.5% under SSP2-4.5 and 33.3% under SSP5-8.5, while longitudinal displacements are expected to rise by 15.4% and 24.9%, respectively. Furthermore, the recent 10-year temperature observation data exceeded the GCM projections since 2015, suggesting that climate change may be accelerating and faster than expected.