Abstract: Green and intelligent construction practices are a current trend in railway tunnels. This study investigates the mechanical properties of prefabricated inverted arch structures during construction using the Yaopo tunnel of the Tianshui Longnan railway as a case study. First, five design modes for these structures are proposed. The modes are then subjected to force tests and theoretical calculations to evaluate the layout of hoisting holes. Next, the structural forces and longitudinal tension under different vehicle loads are tested, and model tests are performed on the connection joints between the prefabricated inverted arch blocks and the cast-in-place arch walls. In addition, tests on foundation grouting and assembly are conducted, and the forces acting on the prefabricated inverted arch structure are validated through practical engineering applications. The results reveal the following: (1) The integral opening double-column scheme for the inverted arch and filling of single-track railway tunnels meets the hoisting safety and construction requirements, with hoisting hole horizontal spacing of 4.6 m, longitudinal spacing of 0.9 m, and a controlled hoisting acceleration of 0.2 m/s². (2) The structural stress of the prefabricated inverted arch blocks remains within acceptable limits under varying construction and assembly machine loads to meet the safety requirements. (3) The V-shaped joint between the prefabricated inverted arch and the cast-in-place arch wall enhances prefabrication convenience and safety, enabling complete tightening of the prefabricated inverted arch blocks at a tension stress of 373 kN. (4) The use of prefabricated inverted arch structures improves overall construction efficiency within the tunnel by over 50%. (5) The contact pressure distribution beneath the inverted arch base is more uniform with prefabricated structures, and the force variation in the arch wall due to the prefabricated inverted arch structure is minimal.

Key words: railway tunnel, prefabricated inverted arch, assembly, construction technology, structural joint, model test