| 摘要 |
PROBLEM TO BE SOLVED: To facilitate a disposal operation for a terminal pipe.SOLUTION: A rubber cone 27 is pressed in a connection member 20a for a steel pipe P through a pipe-like press-in material 35 from an endmost opening of a terminal pipe for an unwidened long-size steel pipe forepoling method to thereby close the connection member. The press-in material is fixed to a terminal pipe terminal by a jig 30, a hose for injection material is run watertightly through the rubber cone to be introduced into the steel pipe, and an injection material is pressed in the peripheral ground from a plurality of lateral holes provided on the steel pipe to permeate the ground and to get solidified, thereby improving the ground. At this time, the injection material never enters the terminal pipe because of the rubber cone. If after the injection, the withdrawal of a mouth reaction jig 30 and a press-in material 35 has ended, tunnel excavation by an excavator is carried on, and the operation is advanced in such a fashion that construction of a steel support 2 and primary coating concrete spraying C are carried out while a part of a terminal pipe 10 filled with no injection material is cut and removed and the injection hose is cut each time the excavation is advanced by 1m. At this time, when the terminal pipe 10 is a steel pipe, the terminal pipe can be easily cut through a slit 13 and when the terminal pipe is a steel-made sheath pipe 10, the terminal pipe is thin and easily cut in a no-slit state. |
