Abstract: The recently proposed prefabricated inverted arch for tunnels constructed using the mining method demonstrates exceptional construction quality and a high degree of mechanization. Using the newly-built Yaopo tunnel of the Tianshui-Longnan railway as a case study, the author systematizes the construction technology for prefabricated inverted arches in tunnels built via the mining method. The author begins by outlining the construction technical parameters and process flow, for the inverted arch structure sumarizing the challenges encountered during its implementation. The author then thoroughly examines the tunnel construction, transportation, assembly, and node construction of the prefabricated inverted arch structure, forming the construction techniques of prefobricated inverted arch structure. Finally, the performance of the prefabricated inverted arch + cast-in-place structure is compared with that of the fully cast-in-place lining structure through field tests, analyzing monitored deformation data to highlight the advantages of the prefabricated inverted arch in terms of structural stability and safety. The research results reveal the following: (1) The prefabricated inverted arch + cast-in-place structure meets the relevant technical standard requirements of the railway tunnels constructed using the mining method. (2) The prefabricated inverted arch structure is hoisted and docked by an assembly machine, greatly reducing the number and type of construction machinery and equipment. (3) The prefabricated inverted arch + cast-in-place structure slightly outperforms the fully cast-in-place lining structure in terms of crown subsidence and horizontal convergence controls.

Key words: single-track railway tunnel, mining method, prefabricated inverted arch; fully cast-in-place lining structure