| 摘要 |
PROBLEM TO BE SOLVED: To provide an excavator and an excavation method capable of reducing quantity of bentonite used when excavating a pile hole.SOLUTION: While rotatably pressing a casing 1 having an injection pipe 2 for injecting a bentonite liquid on an outer peripheral surface, in which the injection pipe 2 has a jetting nozzle 4 for jetting the bentonite liquid in the direction along the outer peripheral surface, in soil while jetting the bentonite liquid from the jetting nozzle 4 by injecting the bentonite liquid into the injection pipe 2, soil in the casing 1 is excavated and removed. A clearance corresponding to a projection width of the injection pipe 2 is formed between the casing 1 and a pile hole wall by rotation of the casing 1, and the bentonite liquid is injected only into this clearance, and is mixed with the soil of a pile hole wall surface, and becomes bentonite-mixed soil of a sticky state, and forms a protective layer for preventing collapse of the pile hole wall. When extracting the casing 1, since the bentonite-mixed soil of the sticky state exists between the casing 1 and the pile hole wall, the casing 1 can be easily extracted.SELECTED DRAWING: Figure 1 |
