| 摘要 |
PURPOSE:To increase the bearing force of a pile by a method in which cement milk is injected while excavating the ground by an auger screw, a steel pipe is penetrated to a place deeper than the bottom of an old cavity, excavation is further made to the support layer, and then a rich-mix cement milk is injected. CONSTITUTION:A steel pipe 2 and an auger screw 3 are turned by a driver 1, and a lean-mix cement milk is injected from the tip of the screw 3 while excavating the ground and mixed with excavated soil with stirring. When the tip of the steel pipe 2 reaches a place deeper than the bottom of an old cavity B, the driving of the steel pipe 2 is stopped, an additional screw 3' is connected to the screw 3, and excavation and injection of the lean-mix cement milk are continued. When the tip of the screw 3' reaches the support layer, the lean-mix cement milk is switched to a rich-mix cement milk, and while injecting the rich mix cement milk, the cement milk is mixed with excavated soil while stirring to form a foot-protecting milk C. The screws 3 and 3' are pulled up, and a custom- made pile (a) is penetrated into the excavated hole. |
