BRANCHED SHIELD EXCAVATING METHOD, AND SHIELD EXCAVATOR CAPABLE OF BRANCHED EXCAVATION

摘要

PROBLEM TO BE SOLVED: To provide a branched shield excavating method and a shield excavator capable of preventing settlement or collapse of natural ground, completely restoring a drum member to a condition before branch-starting, restricting increase of machine length in the shield excavator, securing bending performance, and simplifying structure. ;SOLUTION: This shield excavator 1 is provided with a cutter disc 2, a drum member 3, an excavator main body on the inner side of the drum member 3, and an inner drum member 5 engaged inside the drum member 3 to be relatively slidable in a tunnel axial center direction, where the inner drum member 5 is composed to be changeable between a first position for main tunnel excavation where the inner drum member 5 is overlapped with the inner side of the drum member 3, with back end parts of both drum members 3, 5 close to each other, and a second position for forming a branch-starting hole in which the inner drum member 5 is extended backward from the back end part of the drum member 3.;COPYRIGHT: (C)2001,JPO