Key Technologies and Applications of Smart Maintenance for Metro Rails Based on Lifecycle Management

China's metro system ranks among the top in the world in terms of both its total operational mileage and the scale of planned construction. As the metro system enters a phase where construction and operation are given equal priority, there is an increased demand for improved management capabilities in metro operation and maintenance. This paper investigates the business requirements for lifecycle management of metro rails, exploring key technologies such as coding standards for individual rails, attribute data standards, the implementation of electronic tags, and service life evaluation models. A lifecycle management information system for metro rails has been designed and developed, which supports rail degradation prediction and optimizes maintenance and replacement decisions. This paper focuses on the system's technical architecture and core functionalities. The system has been successfully implemented on the actual lines of Tianjin Metro, effectively meeting operational requirements and yielding positive application outcomes.