Comparative Study on Buffeting Performance of Sutong Bridge Based on Design and Measured Spectrum

The recent development in structural health monitoring (SHM) technology enables the buffeting responses of bridges to be evaluated in a more realistic manner. In this paper, the buffeting responses of the cable-stayed Sutong Bridge with a main span of 1,088 m is analyzed with the wind spectra used in the design phase and those obtained experimentally from a long-term SHM system to compare the actual buffeting response with design predictions. The autospectra of longitudinal and vertical fluctuating wind components are derived from the in situ strong wind data recorded by the monitoring system. The buffeting analysis is accomplished in the time domain with the aeroelastic effect included. Compared with the buffeting responses obtained from the measured spectrum, the girder responses from the design spectrum are larger in the horizontal direction and smaller in other directions, whereas the tower responses are larger and thus relatively conservative.