| 摘要 |
PROBLEM TO BE SOLVED: To provide drilling equipment capable of rapidly and reliably performing construction of a sheet pile in hard soil.SOLUTION: Drilling equipment 1 has a hammer bit 14 attached to a rod, which is supported in such a rotatively driveable manner, via a down-the-hole hammer 12, and drills a hole by applying an impact on soil while making the hammer bit 14 rotated by an operation of the down-the-hole hammer 12. The plurality of hammer bits 14 are provided. Each of the hammer bits 14 has its center of gravity positioned on a rotational axis. The hammer bits are arranged in different height positions so that the adjacent hammer bits cannot overlap each other and interfere with each other in a plan view. |
