| 摘要 |
PURPOSE:To make it easy to obtain a necessary site by excavating a multiple- connection type shaft up to a specific depth, turning a shield machine for adit excavation approximately in the horizontal direction, and excavating and forming an adit horizontally from the shaft continuously. CONSTITUTION:A shield machine 1 constituted of a main shield machine 5 and auxiliary chield machines 8A and 8B as a unit is lowered about horizontally to the ground to excavate, and a shaft 2 having an eye-glass shaped section is excavated and formed. After that, with the exception of the main shield machine 5, the auxiliary shield machines 8A and 8B are turned approximately 90 so that an excavating direction coincides with a required horizontal direction. Then, tunnels 3A and 3B are respectively excavated by the shield machines 8A and 8B by giving reaction force to circular segments while assembling the circular segments 11. Segment units 14 are built-up to curved sections. According to the constitution, a necessary site can be easily obtained by reducing and narrowing a sectional area of the shaft 2. |
