| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for preventing a lining body from floating up, which can surely prevent the lining body from floating up by buoyancy of groundwater, when a shield machine is propelled. SOLUTION: A drainage device 40 is mounted in the mouth of a grout hole 38 of an invert portion of a U-shaped lining body 35 or an annular lining one 36. The drainage device 40 includes: a first on-off valve 41 which is connected to the grout hole 38; a cross joint 42 which is connected to the first on-off valve 41 and which enables a channel to branch off in three directions; and a preventer 43, a drain hose 44 and a hose 45 for injecting a back-filling material, which are each connected to the cross joint 42. COPYRIGHT: (C)2010,JPO&INPIT |
