| 摘要 |
PROBLEM TO BE SOLVED: To provide an excavator capable of correcting a track of the excavator with high precision by a comparatively simple configuration when constructing a curved pipe roof and to provide a construction method for a multiple circular arc tunnel by use of the excavator. SOLUTION: This excavator 1 is provided with at least a cylindrical steel shell body 11 arranged in front of a curved steel pipe P for the pipe roof and provided with a cutter face 12 at its tip and a pipe passage 14 for feeding a fluid and a pipe passage 15 for recovering dug soil which are arranged in the steel pipe P. Expansion bodies 2A, 2B, 2C changing their sizes in accordance with amount of supplied fluid are provided in at least three sections or more in the peripheral direction on an outer peripheral face of the steel shell body 11, and pressing force of the expansion bodies against the ground is adjusted by changing sizes of respective expansion bodies to control the direction of excavation of the excavator 1. COPYRIGHT: (C)2008,JPO&INPIT |
