Review of Connection Methods for Assembled Metro Prefabricated Components

［Objective］ The connection methods of prefabricated concrete components are crucial for the installation efficiency and structural stability of assembled metro systems. However, current research predominantly focuses on localized analyses, lacking a systematic review and comparison of these connection methods. Therefore, it is essential to comprehensively summarize the current research status and technological advancements in connection methods for prefabricated metro components, providing a scientific basis for technological selection and design optimization. ［Method］ The research progress in China and abroad is systematically sorted, focusing on five mainstream connection methods: cast-in-place connection, steel grouting sleeve connection, bolted connection, welded connection, and steel component quick connection. Specific engineering cases are examined to analyze the strengths, weaknesses, and applicable scenarios of each connection method. ［Result & Conclusion］ Cast-in-place and steel grouting sleeve connections, as a wet connection method, exhibits high load-bearing capacity and reliability. However, these methods involve longer construction cycles and relatively complex processes. Cast-in-place connection is particularly sensitive to construction environment constraints, affecting efficiency. Although steel grouting sleeve connection reduces the amount of casting work, it is technically demanding and has higher costs. Bolted connections, welded connections, and steel component quick connection, as dry connection methods, eliminate the need for wet operations and offer relatively simpler construction. Bolted connection, however, is labor-intensive and has limited load-bearing capacity; welded connection requires high technical proficiency and is sensitive to working conditions. Steel component quick connection, with its advantages of fast construction, reliable quality, and strong load-bearing capacity, is particularly suitable for complex working conditions and space-constrained environments.