Objective With the growth of metro operation years and the continuous expansion of mileage, the number of tunnel defects keeps on rising, accompanied by coupled effects. Existing evaluation methods can hardly reflect the overall structural health conditions comprehensively. To enhance the scientific basis of operation and maintenance decision-making, it is necessary to establish a standardized management system to achieve standardized management and comprehensive evaluation of defect information, thereby ensuring the long-term operational safety of metro tunnels.

Method First, based on statistical results of shield tunnel defects from various provinces and cities, the common defect types are summarized. From the perspective of the coexistence of defects, the necessity of comprehensive structural evaluation is discussed; from existing defect evaluation methods, the shortcomings of monotonous evaluation objects and fragmented evaluation systems are identified. Then, the database concept is introduced to organize, standardize, record, and manage all inspection information related to each defect type. Finally, a comprehensive structural health evaluation method for shield tunnel rings is designed by combining monotonous defect structural health evaluation and mathematical model approach, and an actual case is evaluated.

Result & Conclusion  Since the defect types serving as the management target are representative, and the defect information records are complete and mutually independent, the structural health evaluation of monotonous defects can be efficiently completed. By integrating the database with the mathematical model method, problems of difficult data acquisitions and nonstandard data formats are solved, an efficient comprehensive evaluation is achieved, allowing a process-oriented comprehensive evaluation of the structural health conditions of all shield tunnel rings within a specified section.