| 摘要 |
1311113 Tunnel ring ILSEDER HUTTE 24 June 1970 [25 June 1969] 30564/70 Heading E1F A tunnel ring is assembled from part-cylindrical steel sheets 1a, Figure 6, welded at one end to a port-annular steel bar 3 and at the other end to a port-annular T-section 4. Circumferential joints between abutting rings are formed by bolts 10 and weld 11. Longitudinal joints between sheets 1a, Figure 4, are bridged by plates 2 bolted to sheets 1a. The ring is covered by a sheath 5 extending between bars 3 and T-sections 4. The sheath may comprise ribs 5a of trapezoidal cross-section welded to sheets 1a. The cavities within and/or between the ribs may be filled with expanded clay or glass, foamed blast furnace slag, foamed plastics material or lightweight concrete. Alternatively, the sheath may consist of concrete reinforced by steel inserts welded to the bars 3 and T-sections 4. The sheath is covered by protective layer 9 which is trapped at longitudinal joints by gasket 8 under plate 2, and at circumferential joints by angles 12 held in a recess in bars 3. One of the sheets la may form a key-piece in the ring, the end edges of the steel bar and T-section of the key-piece being radially directed. |
