Temperature behavior of long-span cable-stayed bridges by using unified analysis

Varying temperatures significantly affect long-span cable-stayed bridges. However, previous studies on the temperature behavior of bridges were either limited by finite sensors, failing to capture the accurate relation between the temperature and responses, or constrained to a “divide-and-conquer” strategy, requiring considerable manual intervention. This study develops a unified approach to the investigation of thermal behaviors of cable-stayed bridges by integrating heat-transfer analysis and structural analysis based on the same refined global 3D finite element model. A navigation channel bridge of Hong Kong‒Zhuhai‒Macao Bridge is used as the testbed. First, the heat-transfer analysis is conducted based on thermal boundary conditions carefully determined from real-time ambient temperature, wind, and solar radiation, which are tailored for each surface to reflect the influence of the geometric configuration and temperature difference. Then, the detailed temperature distribution results are automatically converted to thermal loads, and thermal elements are changed to structural elements to calculate the temperature-induced responses. Results show that temperature has a significant effect on the structural responses of the bridge. The calculated temperatures and temperature-induced responses are in good agreement with their measured counterparts, verifying the effectiveness of the proposed unified approach to investigating the temperature behavior of cable-stayed bridges.