| 摘要 |
PURPOSE:To minimize the effect on natural ground around an excavated area by enveloping a shield cutter installed at the front of a shield machine in such a fashion that it may be rotated, and what is more, driven formed and installing an edge cutter which is preliminarily installed and, which is cylinder-shaped and engaged with the shield cutter and designed to be rotated and propelled as well. CONSTITUTION:A shield machine is set in an underground structure or the like. A cutter slide jack 33 is contracted with a projected engagement pin 34 of a shield cutter 3 and driven forward with the shield cutter 3 by way of a shaft 31 where a rotary force is provided by a rotary motor 32. Since the engagement pin 34 is engaged with a propulsion engagement projection 41 and rotary engagement projection during that time, the rotary force and driving force of the shield cutter 3 are transmitted to the edge cutter 4 and pressfitted in the natural ground. The excavation by the shield cuter 3 is carried out in the natural ground inside the edge cutter 4 separated from the peripheral natural ground. This construction makes it possible to protect the ground from rising and sinking. |
