BEDROCK DRILLING DEVICE AND BEDROCK DRILLING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a bedrock drilling device and a bedrock drilling method, suitable for drilling downward extending holes in a bedrock while partly overlapping each other.;SOLUTION: In the state that a guide rod 20 is inserted into an already drilled second hole 24B, a closing member 30 is inserted into an already drilled first hole 24A adjacent to the second hole 24B to close a communication area between the first hole 24A and the second hole 24B over the total length of the first hole 24A. The closing member 30 prevents cuttings formed when drilling a third hole 24C adjacent to the second hole 24B from entering into a slit groove including the first hole 24A through an annular gap 26 between the outer periphery of the guide rod 20 and the inner wall of the second hole 24B.;COPYRIGHT: (C)2012,JPO&INPIT