| 摘要 |
PROBLEM TO BE SOLVED: To provide a construction method of an arch-shaped preceding support by which a strong arch-shaped preceding support can be constructed easily even when the shape of an arch section is flat. SOLUTION: A plurality of tube bodies 10 with joints are inserted and buried in a natural ground 2, which is to be the arch section of a tunnel, along the arch section while connecting the tube bodies 10. Both end sides of the tube bodies 10 with the joints are fixed to reaction plates 5A, 5B mounted on pilot tunnels 1A, 1B. After steel wire bundles 20 penetrating the plurality of the tube bodies 10 with the joints are arranged along the arch section 4, the tube bodies 10 with the joints are filled with concrete to construct the preceding support 10R serving as an arch-shaped underground structure. Then, while taking a reaction force with the reaction plates 5A, 5B, fixed ends 20a, 20b of the steel wire bundles 20 are fixed to the reaction plates 5A, 5B in a state that a tensioning force is applied to the steel wire bundles 20 so that a compression force may be applied to the preceding support 10R in advance. COPYRIGHT: (C)2009,JPO&INPIT |
