EXISTING TUNNEL REMOVING METHOD AND SHIELD MACHINE FOR USE IN REMOVING EXISTING TUNNEL

摘要

PROBLEM TO BE SOLVED: To provide an existing tunnel removing method which can easily and positively remove steel segments and a concrete layer, and to realize a shortened construction period and reduced construction costs, by firstly cutting and removing the concrete layer covering the internal surface of the steel segments, and then demolishing the steel segments, and to provide a shield machine for use in removing the existing tunnel. ;SOLUTION: A shield machine 1 is advanced from one end of an existing tunnel Ta to the other end of the same, and a cutter head 3 of the machine 1 annularly drives the natural ground around the periphery of steel segments S of the existing tunnel Ta. At the same time, a concrete cutting device 7 of the machine 1 cuts a concrete layer C on the internal periphery of the steel segments S, and a segment demolishing device 9 of the machine 1 demolishes the steel segments C at a portion where the concrete layer C is removed, followed by carrying the segments C to the outside of the existing tunnel Ta.;COPYRIGHT: (C)2001,JPO