| 摘要 |
PURPOSE:To permit an expandible shield excavation work to be performed in parallel at optional positions while performing the main shield excavation. CONSTITUTION:A side expansion unit 42 having a slide cutter 32 is extended from the shield wall for excavation on the way of excavation by the main shield excavator. Afterwards, a circumferential excavation unit 50 having a slide cutter 48, which is housed in the side wall of the unit 42, is advanced from the side wall to perform excavation circumferentially along a guide 56 provided for the unit 42 in order to construct an expanded shield construction work. |
