| 摘要 |
<p>A sheath assembled from separate support elements is stiffened by steel profile arcs assembled from separate segments. It is used in cladding for tunnel walls, preventing earth movement and collapse. The support elements (7) lie loosely against each other, and are held in position by the profile arcs (1,2). They pref. consist of steel profiles embedded in an insulating filling substance, pref. hard plastic foam, or a similarly embedded steel profile sheet. The arcs can be of double-T-profile steel, with shanks (3-6) overlapping the support elements. They are pref. fitted for splaying, so as to increase their dia.</p> |
