UNDERGROUND BORING METHOD AND UNDERGROUND BORING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an underground boring method with which the direction can be changed even in a hard soil.;SOLUTION: A pilot body 15 having a sloped pressure surface 15a is driven while rotating the pilot body thereby drilling the underground almost linearly. The boring device is propelled when the pilot body 15 turns by a predetermined angle from the predetermined turning position and the driving direction is changed by this method.;COPYRIGHT: (C)2001,JPO