| 摘要 |
PROBLEM TO BE SOLVED: To reduce the generation of cracks by suppressing lateral forces acting on segments. SOLUTION: A shield machine 10 is provided with an excavating body 12 and a cutter head 14. A thrusting shield jack 30 is provided in the excavating body 12. A spreader 50 abutting against a segment 32 is disposed at the extensible end of the shield jack 30. A section where the spreader 50 abuts against the segment 32 is made slidable along the radial direction of a tunnel. The spreader 50 has a body 50a fixed to the end of the extensible plunger 30b, an abutting plate 50b slidably supported by the body 50a in the radial direction of the tunnel and abutting against the segment 32 when the plunger 30b is stretched, and a sliding member 50c interposed between the body 50a and the abutting plate 50b. COPYRIGHT: (C)2004,JPO
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