Abstract:  Traditional tunnel inspection methods struggle to satisfy the demands of largescale tunnel inspection in a timely and effective manner in China owing the large number of operational railway tunnels. In this study, a costeffective and efficient railway tunnel inspection is realized by developing the new tunnel inspection technology and optimizing the existing detection methods. First, the tunnel inspection technologies used in China, Japan, and South Korea are investigated, and the stateoftheart of the tunnel inspection technology development is introduced from the aspects of image inspection technology, nondestructive detection technology, and integrated inspection technology. Based on the current situation, the development trends in operational railway tunnel inspection technology, rapid comprehensive inspection, intelligent data interpretation, and collaborative assessment of tunnel status are proposed, and the tunnel inspection mode applicable to the actual situation of operational railway tunnels in China is analyzed. Results show that tunnel inspection should be focused upon before tracklaying. Comprehensive and real tunnel initial state information should be ensured, and the construction of tunnel state information database should be speeded up to realize the dynamic cycle detection of railway tunnels in the operation period, reduce cost, and increase efficiency based on rapid, comprehensive, and intelligent tunnel detection technology system.

Key words: railway tunnel, operation period, inspection technology, inspection model, dynamic cycle