| 摘要 |
In the driving of galleries with a shield, the revetment of the tunnel is introduced by concreting on site by step immediately behind the shield. In order to avoid interrupting the advance of the shield during concreting, besides the fixed rear part of the shield (6), a mobile part has been provided made up of a set of lamellae (7). In principle this part remains still during the continuous advance of the shield, and it will be pulled forward in the shield lamella per lamella only at the time of concreting the segments, and it will then remain still with respect to the rock, until the new concreting step. |
