Seepage control at the bottom of the site
1.5 mm HDPE geomembrane was selected. The upper and lower layers of the geomembrane are covered with a geotextile layer of 300g/m2. (The geotextile for the bottom blind ditch is 400g/m2). The supporting layer is 200 mm clay layer. And the protective layer is 300 mm clay layer.
Before laying HDPE geomembrane, debris that may damage HDPE geomembrane should go out at the bottom of the landfill reservoir. Such as tree roots, broken glass, stones and so on.
When laying backfill, the compactness of backfill should be ≥ 95%. And the weld lap width of HDPE geomembrane ≥100mm.
Slope seepage control
Some areas have steeper slopes. In this case, the supporting layer and protective layer are difficult to lay. Therefore, the treatment of slope seepage prevention is different from that of ground floor seepage prevention.
Slope seepage control generally has two ways.
1. First, the grouting slope protection is used as the supporting layer of the impervious layer. Then anchor HDPE geomembrane with shooting nails. Finally, a layer of bagged soil is prevented from being used as a protective layer.
2. The second is to lay a layer of bagged soil instead of shotcrete as the supporting layer. The rest is the same as the first method. This method is more economical than the first one.