Patent ID: 7614826

Claim:
A method for waterproofing and draining off seeped water in hydraulic structures ( 10 , 31 , 41 , 52 ), in which a waterproof sheathing, consisting of elastically deformable geomembrane sheets ( 11 ), is applied and secured to a surface area of a wall of the body of the hydraulic structure ( 10 , 31 , 41 , 52 ), providing said sheathing with a one-way water drainage valve ( 13 ) for draining off the seeped water collected behind the waterproof sheathing, comprising the steps of: defining drainage points for draining off the water in pre-established positions of the waterproof sheathing; providing, in each of the pre-established drainage point, a one-way drainage valve ( 13 ) having a water discharge aperture in said waterproof sheathing; orienting said water discharging aperture of the drainage valve 13 in a natural downflow direction of the water and providing said drainage valve ( 13 ) with a flat flexible valving member (M), overlapping the discharging aperture; subjecting the flat valving member (M) to a differential pressure of the water acting on opposite faces of the waterproof sheathing; and causing automatic opening and closing of the drainage valve ( 13 ), by the pressure difference of the water arising on the opposite faces of the flat valving member (M) of the drainage valve ( 13 ), characterised by the steps of: providing said drainage valve ( 13 ) on a wall surface of the hydraulic structure ( 10 , 31 , 41 , 52 ); and downwardly draining the seeped water by gravity.