Anomaly diagnosis of stay cables based on vehicle-induced cable force sums

Abstract

Stay cables are one of the most critical load-carrying components for cable-stayed bridges. Cable damage or performance degradation can affect the normal operation of bridges. Therefore, it is essential to evaluate the service performance of cables in real time to ensure bridge safety. In this paper, an anomaly diagnosis method for stay cables based on vehicle-induced cable force sums (VICFS) of cable pairs (defined as two symmetric cables upstream and downstream) is proposed. First, the theoretical relationship between the vehicle load and VICFS was derived through mechanical analysis. Second, a new anomaly-sensitive warning index was established based on the above derivation, and the anomaly diagnosis for stay cables was achieved by combining it with the X-bar control chart. Then, according to finite element simulation, the variations in VICFS in different cases were analyzed to verify the rationality of the theoretical derivation and the established warning index. Finally, an engineering application to an in-service cable-stayed bridge was carried out to validate the feasibility and effectiveness of the anomaly diagnosis method. The results show that the proposed method can accurately detect and locate damaged cables, which can be successfully applied to monitor the long-term performance of stay cables.