| 摘要 |
<p>Described is a universally usable and durable cover structure formed of a framing and a flexible plastic sheet. The framing consists of a metal grid structure onto which the flexible plastic sheet is shrunk or welded. In a preferred embodiment shown in FIG. 3, a thinner and closer-meshed mesh structure overlays the grid structure 1. This embodiment employs an upper and a lower plastic sheet 2a and 2b, respectively, connected to one another in such a manner that the grid structure and mesh structure are sealingly enclosed therebetween. Further described are preferred uses of the cover structure as for the construction of water retention structures.</p> |
