Waterproof Membrane Main areas
In recent years, the application of waterproof membrane in water conservancy and hydropower project is a mature technology, mainly used in earth dam, concrete dam, vertical cut-off wall, channel and pool and tunnel engineering, etc. When selecting waterproof membrane material, To meet the normal load under the strength and deformation requirements of the mechanical properties, in particular, pay attention to the following factors:
The main area of application of waterproofing membrane, earth dam dam project is designed to prevent the dam or dam foundation leakage, both for the new dam and for the old dam repair and heightening, including: (1) (2) double lining, both for the sloping wall, but also to do the upstream bedding; (3) built on the foundation of the dam on the foundation, for double lining, single-layer film for the wall; (5) There is a weak layer or easy to damage in the bedding area, with a single layer of waterproof membrane covered with a geogrid or high strength, high modulus geotextile reinforced soil; (6) to waterproof (8) folding line cut-off wall, in the new dam with the construction of land-by-block welding up to extend; (7) vertical seepage wall through the dam can be used for new dams or old dam; (10) for the two compressive different materials of the dam, at the interface of the two materials on the dam with a waterproof membrane to prevent cracks in the leakage of the dam; (12) with a waterproof film to repair the foundation loopholes, etc. Waterproof film is commonly used in the project of a waterproof material. Waterproof film to plastic film as impermeable substrate, and non-woven composite made of soil impermeable material, its impermeability depends mainly on the plastic film impermeability. At present, the domestic and foreign anti-seepage application of plastic film, mainly polyvinyl chloride (PVC) and polyethylene (PE), they are a polymer chemical flexible material, the proportion of small, strong extension, high adaptability to adapt to deformation. Corrosion resistance, low temperature resistance, good frost resistance. The main mechanism is to plastic film impermeable barrier earth dam leakage channel, with its large tensile strength and elongation to withstand water pressure and adapt to the dam deformation; and non-woven is also a polymer short fiber chemistry Material, through the needle or hot tack forming, with high tensile strength and extensibility, it is combined with the plastic film, not only increased the tensile strength of plastic film and anti-puncture ability, and because the non-woven surface rough , Increasing the friction coefficient of the contact surface, is conducive to the waterproof membrane and protective layer stability. At the same time, they have good resistance to bacteria and chemical resistance, not afraid of acid, alkali, salt erosion.
Waterproof membrane life of the problem, mainly by the plastic film is lost seepage barrier depending on the role of the Soviet Union, according to the national standard, the water with a thickness of 0.2m plus stabilizer polyethylene film, working under the conditions of water Life of up to 40 to 50 years, working conditions in the sewage conditions for 30 to 40 years. So the use of waterproof membrane is sufficient to meet the requirements of the dam seepage requirements.