Typhoon- and temperature-induced responses of a cable-stayed bridge

Long-span bridges are subjected to wind and temperature actions. Wind action is generally the governing load of long-span bridges in design, while temperature action is also significant. Accurate separation of typhoon- and temperature-induced responses is thus necessary for in-depth investigation of their effects and comprehensive evaluation of structural performance. This paper separates the temperature- and typhoon-induced responses of the Qingzhou Bridge by using a unified global analysis approach. The field-monitored meteorological data and structural responses collected from the structural health monitoring system installed on the bridge are analyzed in detail, with emphasis on the comparison of those during typhoon Higos (Signal No. 9) and a typical sunny day after the typhoon. Results show that the quasi-static variation of displacement and stress responses are higher on a typical sunny day than those during the typhoon period, which is out of intuition. Through the unified analysis, the temperature-induced responses are calculated, and the typhoon-induced responses can be separated. The temperature- and typhoon-induced longitudinal displacement, mid-span deflection, and stress of the girder are compared. The temperature-induced response accounts for a large part of the total quasi-static recording either on a typical sunny day or during the typhoon period, whereas typhoon caused significant dynamic responses. The typhoon-induced quasi-static and dynamic responses are also in good agreement with the wind tunnel test results. This case study demonstrates the effectiveness of the unified global analysis in separating the temperature effect.