| 摘要 |
<p>The tunnelling system includes forcing forwards prefabricated concrete members matching the shape of the previously cut tunnel, to form a permanent lining. The machine travelling on rails laid inside the concrete members themselves is used to push the next member forward behind a shaped leading member. This machine has sets of vertical cylinders which extend to the top and bottom of the tunnel so that a row of horizontal double ended cylinders can be inserted between the bottoms of two concrete members and another row between the tops, to advance the next member. Similarly, horizontal cylinders insert vertical double ended cylinders between the sides.</p> |
