Friction anomaly alarm for bridge sliding bearings under operating environmental conditions. (1st March 2023) - Wu, Guang-Ming
Highlights: A temperature-displacement hysteresis model was proposed by considering the friction of bridge bearings. An anomaly alarm approach was established using the extracted sliding friction indicator from the hysteresis model. The friction of sliding bearings fluctuates at the same temperature and slightly decreases with an increase in the temperature. The anomaly alarm approach can effectively detect the mild increase in sliding friction of bridge bearings under operating environmental conditions. Abstract: Bridge sliding bearings are critical elements to ensure the acceptable free expansion of bridges. Abnormal sliding friction implies peeling-off and wear damage of sliding bearings, which pose a threat to bridge safety. In this study, an alarm anomaly approach was developed for the sliding friction of bridge sliding bearings under operating environmental conditions. First, the common linear temperature-displacement relationship was briefly introduced, and a temperature-displacement hysteresis model that involves the sliding friction of sliding bearings was proposed. Then, a sliding friction index was extracted from the temperature-displacement hysteresis model, and the alarm approach for the sliding friction anomaly was constructed using the friction index with the cumulative sum control chart. Subsequently, the entire implementation procedure of the alarm anomaly approach for sliding friction was systematically described. Finally, an engineering application of the anomaly alarm approach was performed on a cable-stayed bridge with sliding bearings. The results indicate that the proposed temperature-displacement hysteresis model can straightforwardly reflect the sliding friction of the bearings, and the proposed anomaly alarm approach can effectively detect the mild increase in sliding friction of bridge bearings.