REINFORCING STRUCTURE OF CENTER PILLAR OF BINOCULAR-SHAPED TUNNEL, AND CONSTRUCTION METHOD FOR TUNNEL

PROBLEM TO BE SOLVED: To provide a reinforcing structure of a center pillar which is provided in a central advancing drift of a binocular-shaped tunnel, inhibiting a wall-shaped column from being deformed by the excavation of an advancing main tunnel. SOLUTION: The center pillar 11 is provided in advance as a shared supporting structure in the advancing drift 10 which is positioned between the advancing main tunnel 20 and a reversing main tunnel 30 provided in parallel in a close state. A back-filling material layer 13 with a predetermined thickness is formed in a reversing main tunnel-side drift 12 of the advancing drift 11. Air mortar 14 with a predetermined layer thickness is infilled between the wall-shaped column section 11d of the center pillar 11 and timbering on it. The timbering of the center pillar 11 is performed in the excavation of the advancing main tunnel 10. After that, the reversing main tunnel 30 is excavated while the reinforcing structure of the drift 12 is removed, an invert of the main tunnel is excavated, and secondary linings 21 and 31 of each main tunnel are performed. COPYRIGHT: (C)2006,JPO&NCIPI