Study on key technology of tunnel fabricated arch and its mechanical mechanism in the mechanized construction

•The primary support system of the high-strength confined concrete arch is developed in large section tunnel.•The intelligent arch installation equipment and other matching devices are developed.•Mechanized construction technology of the fabricated confined concrete arch is put forward.•Mechanics mechanism of fabricated arch is studied in the mechanized installation process.•The field application of mechanized construction of fabricated arch for large section tunnel is conducted.