| 摘要 |
<p>An arcuate concrete section (13) for forming a tunnel has a groove (12) around its edges for accommodating a rectangular frame sealing ring (11) of moulded rubber for sealing adjacent sections (13) together. The sealing ring (11) has a section (Figure 3) with holes (20, 21, and 22) and grooves (23) for allowing distortion as the concrete sections are forced together edge to edge. At the corner of the sealing ring the section is moulded solid (Figure 6), but with larger grooves (34) to allow for distortion.</p> |
