| 摘要 |
<p>The procedure consists of excavating a tunnel with an appropriate machine (2) and fitting a tubular lining (7,8) inside it, using a stage in which the tube members are sectioned lengthwise and folded so that they can be inserted through an existing section of lining and then deployed inside the next excavated portion of the tunnel. The tunnelling machine (2) operates independently of the lining operation, and it comprises an anchoring unit (3), a thrust unit (4) and an excavation section (5). The machine operates in a series of successive stages, comprising anchoring, pushing the excavating section forward, and drawing the anchoring unit behind it. The lining members are of two types (7, 8) - an outer lining of metal or a synthetic material (7), and an inner one of metal or concrete. The inner one can be omitted or formed by injecting concrete after the outer one has been positioned. <IMAGE></p> |
