| 摘要 |
PROBLEM TO BE SOLVED: To enable recovery of an open shield machine at a destination side without constructing a vertical shaft, and construction by an open shield method even at a place where construction of an earth retaining structure is difficult for constructing the vertical shaft.SOLUTION: An open shield method is for sequentially burying in a vertical direction concrete box bodies by repeating the following steps for: installing a propulsion jack on an inner side of side wall plates on right and left, and excavating and discharging sediment in front of an open shield machine that has front, rear, and top surfaces open, or sediment in front of the opening in the top surface; advancing the shield machine by extending the propulsion jack and using the concrete box body for obtaining reactive force; and lowering a new concrete box body from above to behind the propulsion jack that has been contracted in a tail part of the shield machine, and installing the concrete box body by fixing it to the existing concrete box body. Upon arrival at a destination, the open shield machine is closed at front and rear without constructing a destination vertical shaft, and lifted using the jack, and at the same time putting a gap filler into a lowe part of the open shield machine from an injection hole of the open shield machine.SELECTED DRAWING: Figure 2 |
