Measured Buffeting Response of a Long-Span Suspension Bridge Compared with Numerical Predictions Based on Design Wind Spectra

Abstract

Wind-induced vibrations of the Hardanger Bridge deck were studied with reference to turbulence characteristics at the bridge site to evaluate the performance of the state-of-the-art methods for buffeting response analysis. Long-term monitoring data from an extensive monitoring system were used to obtain the bridge vibrations and wind characteristics. The acceleration response of the bridge was calculated in the frequency domain using multimode buffeting theory. Design regulations were used directly and also modified using measurement data to deduce the wind turbulence spectra. The aerodynamic properties of the bridge section obtained from previous wind tunnel tests were used in the analyses. The predicted root mean square acceleration response was compared to the measured response. The analysis using the design methodology gave underestimations of the measured responses. The use of average values of wind statistics obtained from the monitoring data only slightly improved the results. When the variability of the wind field was reflected into the design method by using the probability distributions of the wind field parameters, more satisfactory design curves were obtained.