| 摘要 |
PROBLEM TO BE SOLVED: To provide an adit construction method which eliminates an error of locational search for an adit construction apparatus present under the ground, from above the ground, to thereby carry out correct search, and to provide the adit construction apparatus. SOLUTION: According to the adit construction method, the adit construction apparatus having a cutter head which is rotated by a driving motor is employed as a leading body, and the ground is excavated by rotating the cutter head, whereby propelling pipes are sequentially propelled in a manner trailing the adit construction apparatus while natural ground cave-in is prevented. According to the method, the adit construction apparatus houses therein a transmission coil, and a magnetic field formed by the transmission coil is detected based on an induced electromotive force generated at a receiving coil set on the ground. In order to search for the location of the adit construction apparatus, based on the intensity of the detected magnetic field, the transmission coil is formed of a pair of coils having axial directions orthogonal to each other, and thus the magnetic field formed by the transmission coil is detected. COPYRIGHT: (C)2004,JPO |
