METHOD AND UNIT FOR DRILLING HOLE IN CONCRETE

PROBLEM TO BE SOLVED: To drill a hole, for example, in a structure of reinforced concrete construction. SOLUTION: In the drilling unit 1 for use, a first nozzle head 5 the leading head of which is equipped with two nozzles 4 having discharge openings directed obliquely outward from the central axis of a pipe body 3 is attached to a tip of the pipe body 3 which is supplied with high-pressure water by a high-pressure pump 2. The drilling unit 1 is installed at a position enabling the nozzle head 5 and the pipe body 3 entering a concrete hole 9 together with the formation of the concrete hole 9. The high-pressure water is supplied to the pipe body 3 and ejected from the nozzles 4 while the nozzle head 5 enters the back side of the first concrete hole 9 which is formed while being swung and turned between predetermined angles around the central axis of the pipe body 3. The first nozzle head 5 is replaced with a second nozzle head having a lateral surface with the nozzle 4, and a lateral surface of the first concrete hole 9 is partially cut and extended for forming a second concrete hole 52. COPYRIGHT: (C)2010,JPO&INPIT