Drilling agitation head for steel pipe soil cement pile construction

摘要

PROBLEM TO BE SOLVED: To provide a drilling/agitation head for installing a steel pipe soil cement pile in a hard ground that does not require other heavy machinery and curtails installation period at the same time reducing a cost because a lesser number of heavy machinery is used.SOLUTION: A drilling/agitation head 1 includes a shaft part 2 connected to a drilling rod, a lower drilling blade 3 provided at a tip of the shaft part 2, a pair of upper drilling blades 4 provided above the lower drilling blade, a plurality of co-rotation preventing blades 5 loosely fit on the shaft part 2, and a plurality of agitation blades 6. Drilling performance into a hard ground is improved when three or more of the lower drilling blades 3 are provided around a shaft of the shaft part 2, while suppressing deviation from a drilling shaft center at a time of drilling compared to a conventional two-blade drilling head. The co-rotation preventing blade 5 comprises a blade body 5a and a projection part 5b. Resistance from the ground against drilling is mitigated by making the projection part 5b thinner than the blade body 5a and using a material of higher strength than a material of the blade body 5a.SELECTED DRAWING: Figure 1