| 摘要 |
PURPOSE:To enhance the water-stopping property of a cut-off wall by a method in which the lower part of a pit is closed, compressed air is introduced into the lower part of the pit to cause the level of ground water to lower, the first hardening region is formed under the ground, and the second gardening region is formed in the first hardening region. CONSTITUTION:The ground 32 is drilled by a screw auger with the shaft of double tube 16, and compressed air is supplied through a hose 34 from a compressed air supply source 36 into the inner tube 12. At the same time, a hardener from a hardener feeder 38 is supplied through the hose 34 into the inner tube 12 and injected from the nozzle 18 to form the first hardening region. Before the first hardening region is hardened, the auger is reversely turned, and a hardening accelerator is injected from the nozzle 18 through the outer tube 14 by a grout pump 42. When the auger is pulled up, the hardening accelerator is mixed with the hardener by the stirring blade 24 and reacted with the hardener to form the second hardening region. |
