Global temperature behavior monitoring and analysis of a three-tower cable-stayed bridge

Varying temperature is a major load of long-span cable-stayed bridges. The temperature effect on the structural behavior may mask the influences of other loads. Conventional studies on the thermal behavior of bridges are limited to regression analyses based on measurement or numerical studies of 2D or local 3D models. This study investigated the global 3D temperature behaviors of a three-tower cable-stayed bridge through the integration of field monitoring and unified numerical simulation. A 3D refined model of the bridge with thermal elements was built, and the thermal boundary conditions were determined from environmental field monitoring data for the global 3D heat-transfer analysis. The calculated temperatures agreed well with the field monitoring counterparts. The temperatures were then input into the same global finite element model with mechanical elements for structural analysis. The temperature-induced structural responses, including the structural displacements and forces, agreed well with the measurement counterparts. The temperature-induced structural response variation pattern and sensitivity were summarized and quantified. This unified numerical simulation enables an efficient and accurate analysis of the global 3D thermal behavior of bridges, as compared with the conventional 2D or local 3D simulation.