TUNNEL WATER STOPPING METHOD IN MASTER-SLAVE SHIELD TUNNELING METHOD

摘要

PROBLEM TO BE SOLVED: To reliably stop water at a low cost and to dispense with the removal of a filler when a branch pipe is connected by pressurizing the space surrounded by large and small segments assembled by master and slave shield machines with air after the master and slave shield machines are separated from each other. SOLUTION: After a slave shield machine 2 is separated from a master shield machine 1, the tubular space 5 surrounded by a large-diameter segment assembled by the master shield machine 1 and a small-diameter segment assembled by the slave shield machine 2 is pressurized with air (a). The compressed air (a) is filled from a nozzle 7 fitted to an annular bulkhead 8a for air pressurization. This air pressurization can prevent the sediment and water of the natural ground from intruding into the space 5 in spite of its very simple and easy method. The cost can be sharply reduced as compared with the conventional chemical injection method. A branch pipe can be simply connected by utilizing the space 5. The construction period is shortened, and the cost can be reduced.