| 摘要 |
1,249,332. Tunnels &c. TUBE HEADINGS Ltd. 23 June, 1969 [25 June, 1968], No. 30243/ 68. Heading E1F. A tunnel is constructed by driving tube sections horizontally end-to-end through the ground to form tubes 13, 14, 16, by extending a support structure 19 from one of the tubes to an adjacent tube, and by excavating the ground underneath the structure. Bores such as 20 are augered from within the tubes 13, 14 to connect shuttered windows 15, 18 in the tube 16 and are then cased. Beams 21 are inserted in the cased bores and cemented. Further support means comprising piles 23 or downwardly extending concrete walls may be added. The tubes 13, 14, 16 are then filled with concrete leaving service ducts 25. The ceiling of the tunnel is formed from a layer of gunite. Instead of augering bores 20, further small tubes may be jacked between the tubes. |
