Forward Maintenance Strategies to Prefabricated Assembled Tunnel Disease

In the context of the increasing number of tunnel diseases, ensuring safe and efficient operation throughout the tunnel life is an issue that must be faced now and in the future. Unlike other buildings or equipment, tunnels are a linear longitudinal, self-similar transversely, and buried underground, making it difficult to apply existing maintenance strategies to tunnel structures. For prefabricated assembled tunnels, engineering research and theoretical analysis were used to propose a suitable forward-looking maintenance strategy for the tunnels. The research includes: firstly, summarizing the types and causes of prefabricated assembled tunnel diseases, proposing a five-layer disease classification method and a three-world, eight-door disease cause classification method. Then, the special characteristics of tunnel structure and diseases are analyzed to reveal the special characteristics of tunnel maintenance. Then, the prerequisites of maintenance and the purpose of maintenance are analyzed from the tunnel service requirements and perspectives. Then, the macro dynamic evolution mechanism of prefabricated assembled tunnel disease is proposed based on the classification of the three boundaries and the eight causes of disease. Finally, a pre-collective maintenance strategy applicable to tunnels is proposed based on the evolutionary mechanism and maintenance specificity. The research results are not only applicable to prefabricated assembled tunnels, but also to cast-in-place tunnels, and also have theoretical guidance and engineering reference significance for underground structure-type projects.