Method and device for laying down and tensioning an impermeable cover for hydraulic works in loose material

摘要

A method and a device suitable for laying down and tensioning an impermeable cover comprising a plurality of geostrips (20) for protection of hydraulic structures (10) consisting of loose material, such as a dam, canal, and/or water basin. A plurality of trenches or grooves (14) are excavated into the soil (12, 13) of the hydraulic structure (10), all running in a predetermined direction; each trench (14) is shaped to have a finished inner surface suitable to come in contact with the geostrips (20) provided by a compactable, inert loose material having a fine particle size, for example less than 0.6-0.5 mm. In the case of soils containing inert rocky materials or materials with high granulometry, each trench (14) can optionally include a layer of drainage material (15). The laying down of the impermeable cover consisting of said plurality of geostrips (20), is then carried out resting the geostrips (20) in contact with the soil surface, bridging the trenches (14); the geostrips (20), are sealed along overlapped edges, pushed into a first set of alternate trenches (14A), and locked by a first ballast material (22), leaving the geostrips (20) bridging a second set of alternate trenches (14B) adjacent to the previous ones. The geostrips (20) are then tensioned by pushing and locking them into the second set of trenches (14B) by a second ballast material (22).