| 摘要 |
The flood protection barrier (1) is made from prefabricated parallelpiped blocks (2) e.g. of concrete or metal, laid end to end and fastened together with keys or pegs (2b). A line of blocks is then covered by a waterproof membrane (6) that has its lower edge buried in the ground and anchored e.g. by wedges or expanded foam, and its upper edge held in place by temporary fastenings (7) such as clips, straps or clamps. When necessary the surface of the blocks can be covered with a layer of a soft material such as felt to prevent the membrane becoming pierced or torn. A higher barrier can be constructed from two rows of lower blocks, with the gap between them filled with sand or gravel, and a single row on top.
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