| 摘要 |
PURPOSE:To improve the utilizability in the utilization of the inner cavity of a tunnel by allowing the interval between a central shielding machine and the side shielding machines on both sides to be adjusted, arranging segments having different length and executing the reinforcing covering at the center part of the vacant section. CONSTITUTION:Side shield machines 5a and 5b are installed in slidable manner in the direction direction perpendicular to the axis of a tunnel on both the sides of a central shielding 9, and the excavation width of the tunnel is varied by adjusting the slide quantity by a width spreading jack 17. Then, a plurality of the first segments 29 are arranged at the circular part of the glasses-shaped tunnel excavated by a shielding excavating machine, and the second segments 31 are arranged in the axial direction of the tunnel at the joint part between the circular part and the horizontal part. The reinforcing covering construction is executed at the center part of the constituted vacant section, and a pillar wall member P is shifting-installed, and the inner cavity of the side tunnel can be spread. Accordingly, the inner cavity section conforming to the purpose of use can be constructed. |
