A Maintenance Decision-Making Process for Steel Cable Structure System

The performance assessment and enhancement model is the research goal for the maintenance decision-making of a steel cable structure system. Firstly, a novel simplified axial cable force calculation method is introduced. The central safety factor (CSF) and the cable forces' reliability-based safety factor (RBSF) are used for the performance assessment. The multi-level safety factor thresholds for single cable components are preset as the target resistance level, considering the fatigue and corrosion effects. Secondly, the reliability analysis expresses the relationship between each cable component's target resistance and load effect. Thirdly, three failure probability criteria are adopted to comprehensively evaluate the cable structure system's safety factors. The evaluation criterion includes the failure probability criterion of the series structure system (FPC), maximum failure probability estimation method of components (MFPC), and wide-narrow reliability bounds (WNRB). Finally, the maintenance decision-making model for the cable structure system is suggested to enhance the structural performance by two assignment methods: the equal reliability assignment method and the priority assignment method of lower reliability. A cable-stayed bridge case is selected to validate the reasonability of the above algorithms. The research results demonstrated that both the CSF and RBST are valid in evaluating the cable components' performance. The most unfavorable cable safety performance determines the cable force's performance safety. The three evaluation criteria are conducive to assessing the overall cable structure system's safety performance. The maintenance number and location of the cable components can be optimized to meet the target reliability of the cable structure system by two assignment methods.