METHOD OF EXCAVATING TUNNEL, ETC., AND BORING MACHINE THEREOF

摘要

PURPOSE:To make it possible to form an improved longer column in an injection stirring type fore-piling method. CONSTITUTION:In a tunnel excavation method, boring is made by means of a drill unit equipped with a double pipe mounted on a boring machine. An outer casing 21 on the outside of the double pipe is rotated in the first direction, and an inner rod 30 of the double pipe is rotated in the second direction opposite to the first direction to make boring.