Wall punched manner null for existing tunnel reconstruction

摘要

PURPOSE: To excavate a tunnel having a large diameter while crushing a reinforced concrete wall of the existing tunnel. ;CONSTITUTION: A core cutter 17 is placed to the inside of the existing tunnel A, a reinforced concrete wall B is bored from the circumferential surface side with the core cutter 17 to cut a reinforcement D buried in the wall B, and the boring work is carried out at specific intervals in the circumferential direction of the wall B and lengthwise to cut the reinforcement D every small size. In addition, a tunnel excavator 1 is driven by following the core cutter 17, the peripheral ground of the existing tunnel A is excavated with a cutter head 2 having a diameter larger than the existing tunnel A and, at the same time, the wall B of the existing tunnel A is crushed from the rear end with a hydraulic cutter 5 provided to the cutter head 2, and a tunnel having a large diameter is constructed while removing the reinforcement cut in pieces.;COPYRIGHT: (C)1995,JPO