SMALL DIAMETER DOUBLE TUBE HOLE DRILLING DEVICE AND ANCHOR MATERIAL ARRANGING METHOD USING ITS SMALL DIAMETER DOUBLE TUBE HOLE DRILLING DEVICE

摘要

PROBLEM TO BE SOLVED: To improve workability of a natural slope stabilizing construction method for stabilizing a slope by particularly minimally leaving a natural state as it is, by reducing the size and weight by reducing its diameter, by adopting a down-the-hole hammer system rotational impact type double tube hole drilling technology superior in excavation performance.;SOLUTION: In this double tube hole drilling device, an outer bit 6 arranged in an outer peripheral part of an inner bit 5 is constituted to be capable of advancing and retreating to an outer pipe 2, and is constituted for transmitting impact force by a down-the-hole hammer applied to the inner bit 5 to the outer bit 6. The outer bit 6 is arranged to be capable of advancing and retreating inside the outer pipe 2, and the impact force applied to the inner bit 5 is transmitted to the outer bit 6 side by engagement of a rear end part of its outer bit 6 and a locking part arranged on the inner bit 5 side. The workability of anchor material arranging work is improved by applying the small diameter double tube hole drilling device 1 of adopting this down-the-hole hammer system to the natural slope stabilizing construction method.;COPYRIGHT: (C)2007,JPO&INPIT