Long-term cable vibration monitoring and cable tension estimation of a cable-stayed bridge

Abstract

Abstract. This study aims to investigate the applicability of ambient cable vibrations for cable tension estimation and the identification uncertainty and effect of EOVs in the long-term SHM of cable tensions. An advantage of long-term ambient vibration monitoring is that there is no need to close roads for the monitoring campaign once a monitoring system is installed. A disadvantage of long-term environmental vibration monitoring is the difficulty in dealing with uncertainties caused by environmental and operational variations (EOVs). A Bayesian approach to quantify uncertainties in monitoring is thus proposed for the identification of cable tension. Variations of the identified cable tension in the short- and long-term monitoring are examined to discuss the need for normalization of EOVs in damage detection. Long-term monitoring of the cable-stayed bridge showed that it is possible to estimate cable tension using ambient vibration measurements, but that the seasonal variation is greater for longer cables than for shorter cables, making it clear that a trend component of the seasonal variation needs to be taken into account.