Under the action of the geomembrane inclined wall on the upstream dam slope, the friction coefficient between the composite geomembrane and the dam body is generally smaller than the internal friction coefficient of the dam body. Therefore, the anti-slip stability between the composite geomembrane and the protective layer, as well as between the geomembrane and the support layer or the dam body, needs to be calculated and checked. Under the action of the upstream water pressure, a relatively large anti-slip resistance is formed between the composite geomembrane and the support layer behind the membrane. Under normal anti-slip conditions, there is basically no problem with the anti-slip stability behind the membrane.
As a new material, the composite geomembrane has excellent anti-seepage and anti-corrosion functions, good chemical stability, and can be processed according to the actual needs of engineering projects. It has been widely used in the anti-seepage of dams, reservoirs and other water conservancy projects. The composite anti-seepage membrane can also be used as an anti-seepage, anti-corrosion, leak-proof and moisture-proof material in aspects such as roads, reservoirs, sewage ponds, swimming pools, building construction, underground construction, landfills and engineering projects.
When laying the geomembrane on the slope of the pervious material dam, there is a dangerous sliding surface between the upper protective layer, and the stability analysis of the anti-seepage structure should be carried out. It can be paved in ways such as thickening the membrane surface, in a stepped shape, zigzag shape or folded shape. However, the possibility of sliding between the geotextile and the lower cushion layer is very small.
The stability calculation between the composite geomembrane and the upper mortar is the key to the design of the anti-seepage structure. In the analysis of the anti-seepage structure of the diaphragm wall, the equilibrium method can be used for the stability calculation of the protective layer. Earth-rock, dry-laid stone revetment and concrete slab revetment are all permeable. With good revetment performance, in this case, when the reservoir water level drops, the permeable surface of the protective layer also drops, so there is no need to consider the back seepage pressure of the protective layer.