PRECEEDING CUTTER DEVICE FOR BACK-FILL AGENT-INJECTION PIPE IN SHIELD MACHINE

摘要

PROBLEM TO BE SOLVED: To take cut-earth into an excavator and to prevent nonuniform intervenience by forming a recess with an earth removing device ahead of a back-fill agent injection pipe in the rear portion of the circumferential face of the excavator and carrying out excavation by moving a rotary cutter in the recess radially. SOLUTION: An opening 9 is provided in the main body 2 of a shield machine and a bottomed cylindrical outer casing 12 is attached to the rear face of the external wall of a shield machine main body 2. A recess with an earth removing device 10 is provided in the outer casing 12. To excavate a hard ground, the opening 9 is opened by opening a gate 16, a rotary cutter 13 is moved in the radially outward direction of the main body 2 with a cutter mover and projected outwardly beyond the circumferential face of the shield machine main body 2. As cut earth is taken into the recess 11, mud water is introduced from a mud delivery pipe 32 and discharged from a mud discharge pipe 33 in the form of slurry, cut earth is not present any more between the inside perimeter of a tunnel and the shield machine main body 2. After excavation ends, influx of earth is stopped and collapse of ground is prevented by closing the gate 16.