Impervious geomembrane protective surface generally need to do about ten centimeters thick, the protective layer is generally made of soil, the protective layer of soil needs to be processed, generally have to look at the fine sieve, sieve to allow the soil through Diameter should not exceed more than six millimeters, if there are larger particles in the protective layer, easily punctured the membrane. After the protective layer of soil over sieve, need to be rammed again, so that the protective layer is relatively dense, smooth, to ensure that the protective layer rammed over the dry weight in more than one in five, in the ramming process in order to ensure the quality, Also need regular sampling to test it, check the completion of the back fill protection layer, and when using masonry stone masonry, should be done gently, so as to avoid breaking the geomembrane.