| 摘要 |
<p>Method and apparatus for enlarging tunnels in service, characterised by installing a protection shield (60) within the original tunnel to protect through traffic (5) in the section of the tunnel involved in the enlarging operations, consolidating the section to be enlarged on a profile corresponding substantially to the extrados of the enlarged tunnel, demolishing the old lining down to the level of the direct bearings, demolishing the direct bearings and lining the enlarged tunnel.</p> |
