the seepage-proof effect of project composite geo-membrane is mainly depends on the interlayer, the norms of seepage-proof geomembrane is 100-1500g/square meter, in order to guarantee the good seepage-proof effect, the thickness of geomembrane should be less than 500g/ square meter, outer geotextile should be less than 300g, too thin geotextile will reduce the sand stone resisting effect, increasing geomembrane's thickness and prevent sand stone corrosion will influence the seepage-proof effect of geomembrane, composite geo-membrane's norms is less than 800g/square meter, which can reach the seepage-proof standard.
