Title:
AUGER DRILL FOR MAKING SPIRAL GROOVE, SPIRAL-GROOVING METHOD ON PERIPHERAL WALL OF UNDERGROUND HOLE BY USE THEREOF, AND UNDERGROUND PILE WITH SUPPORTING FORCE REINFORCED THEREBY
Document Type and Number:
Japanese Patent JP2709382
Kind Code:
B2
Abstract:
PURPOSE: To provide an auger drill making spiral grooves and the method thereof, in which a PC pile is inserted after spiral grooves have been cut in the process to pull out the auger drill after drilling on the peripheral wall of an underground hole and then cement paste is placed and cured, in this main purpose and increase the supporting force of the pile and improve the construction quality and further, spare the cost by reducing the pile length even in the same conditions in order to get the same required supporting force.
CONSTITUTION: Several bits 3 are formed as a unit at the front end of the lower end spiral blade 2 of an auger drill 1, to drill an underground hole by the spiral blade 2 of the auger drill 1 in order to insert a PC pile. A semi-spherical groove chip 5 having almost the same radius with an overbreak width is attached to the upper part of the external side face of one bit 3 so that the peripheral wall is naturally compacted to the centrifugal direction by the groove chip 5 and hence a spiral groove can not almost formed in the working process in which the hole is excavated by the rotation of the auger drill 1. In the pulling-out process of the rotary shaft, non-excavation type spiral grooves is formed on the peripheral wall of the underground hole by the chip 5, while pulling out the shaft with a deviated angle by means of the centrifugal force and the vibration generated on rotating the auger drill.
Inventors:
Yu Jon Planting
Application Number:
JP14971495A
Publication Date:
February 04, 1998
Filing Date:
May 25, 1995
Export Citation:
Assignee:
Kumho Construction Co., Ltd.
International Classes:
E21B7/00; E02D5/20; E02D5/34; (IPC1-7): E21B7/00; E02D5/34
Domestic Patent References:
| JPS5985028A | ||||
| JPS6347416A |
Attorney, Agent or Firm:
Tsuneo Miyataki