| 摘要 |
PROBLEM TO BE SOLVED: To provide a water cut-off device suitable for cutting off water of a jacking pipe sent out in the ground in a ground improvement and tunnel construction, preventing water leakage of a seal part while allowing jacking and rocking of the jacking pipe, dispensing with its replenishment and a replenishing facility by preventing separation and consumption of a filled sealant, surely providing the stable seal effect by preventing reduction in the seal function, and providing the rational seal effect by adjusting the connecting number of water cut-off units in response to pressure acting on the seal part. SOLUTION: This water cut-off device is provided with an outside seal cylinder 13, an inside seal cylinder 4 relatively movably arranged in the shaft direction on its inside, a first seal member 16 arranged in a longitudinal position of an inner surface of the outside seal cylinder 13 and slidably arranging its tip part on an outside surface of the inside seal cylinder 4, and a second seal member 17 filled between a peripheral surface of the inside-outside seal cylinders 13 and 4 and the first seal member 16. The second seal member 17 is composed of a gelatinous member having predetermined elasticity and plasticity. COPYRIGHT: (C)2006,JPO&NCIPI
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