| 摘要 |
PURPOSE:To enable an excavation blade to be settled into even hard ground by housing a jack between the excavation blade and the lowest layer segment. CONSTITUTION:A cylindrical back plate 3 for sheathing is provided to the upper outside wall 2 of an excavating blade 1 set on the bottom of a pit. A caisson 4 formed by connecting segment blocks 5 is put on the upside of the blade 1, and plural oil-pressure jacks 7 are placed in jack housings 8 formed at an adequate interval in the lower segment block 6. The jacks 7 are driven at a time through a branch metal 10 by an oil-pressure motor 9 on the ground's surface, and when the settlement of the blade 1 becomes uneasy due to hard ground, the jacks 7 are driven by the motor 9 to settle the blade 1. |
