| 摘要 |
PROBLEM TO BE SOLVED: To propel a gripper at the time of an excellent bedrock condition, while propelling a shield jack at the time of an inferior bedrock condition. SOLUTION: A cutter head 3 is installed to the front section of a main beam 1 through a cutter head support 2, a gripper 5 is mounted to the rear section of the main beam 1 in an expansible marmer in the longitudinal direction by thrust jacks 4, and a front support 7 functioning as a skin plate in combination is set up detachably to a pit wall by a jack 11 for the front support. Shield jacks 14 are fitted to the inner circumferential section of the front support 7. |
