Vízügyi Közlemények, 1970 (52. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(33) Hoses alone are insufficient for dam construction, since leakage is likely to occur and the hose is easily displaced by water pressure. The hose must be secured against displacement by sandbags on stakes driven into the ground on the downstream side (Fig. G

). Perfect closure without leakage from hose dams can be attained with the help of plastic foil, the waterside of which must be ballasted by sandbags ( Fig. 6). The pressure which must be maintained in the lioSe is two- to three times the rated diameter of the hose. Hoses to be used for dams must be made of a rot-proof material. I loSes should be capable of resisting an internal pressure three times as high as expected from them under normal conditions. These requirements are met best by plastic hoses reinforced by a fabric of plastic fibres. Hose dams of greater length must be made up of sections of maximum 50 m length. The ends of a section should be Supported on bulkheads made of sandbags, the height of which should equal the head of water maintained in the hose. Filling is readily accomplished using a Small portable, gasoline-engine powered pump, which must take care of occasional leakage losses as well. 10'