Risk analysis and assessment of the electromechanical system in a subsea tunnel operating for ten years

To address potential safety and operational efficiency issues in the long-term operation of the Jiaozhou Bay Cross-Harbour Tunnel’s mechanical and electrical (E&M) systems, this study employs a Bayesian network-based risk assessment model. The model is used to analyze and evaluate problems identified over ten years of operation and maintenance. It quantitatively assesses system performance based on historical failure records. Forward reasoning is applied to determine the system’s overall risk level. Backward reasoning is then used to identify the most probable contributing factors. Based on the analysis results, targeted risk mitigation and maintenance strategies are developed. The study results indicate that the overall operation of the E&M systems is generally satisfactory. However, several key subsystems still require attention and further optimization. These findings can support the development of targeted risk control measures and maintenance strategies to enhance system reliability and safety.