There are mainly two welding construction methods of geomembrane: double seam welding heat sealing and heat welding seam double and single slit extrusion welding. When the adhesive welding line is sheared and peeling checked, only the film can be torn, but there should not be any damage to welded junction. When the adhesive welding line is sheared and peeling checked, only the film can be torn, but there should not be any damage to welded junction (FTB).
1. Flatness: ± 2cm / m2, smooth and straight; 2. Compactness: 95%, it is only after rolling that the geomembrane can be paved; 3. Longitudinal and transverse slope: more than 2%, the contour boundary and structure of landfill bottom must be conducive to percolation.
A. HDPE geomembrane paving 1. Before paving HDPE geomembrane, it is required to have the acceptance certificate related to building projects. 2. Before cutting HDPE film, it is required to accurately measure its related size, and then cut it according to the actual size. Genrally, it is not suitable to cut it according to the diagram. It should be numbered piece by piece, and detailedly recorded in special forms.
1) It should be extended from the bottom to higher place, but it should not be extended too tightly. Leave 1.50% spare geomembrane for local subsidence and stretch. Only taking the actual situation of the project into account, side slope should be paved from top to bottom. 2) The two adjacent longitudinal joints should not be in a horizontal line. They should be staggered over 1m. 3) The longitudinal joints should be over 1.50m away from dam toe and the corner of clubfoot. And they should be located in the plane. 4) Side slope is paved first, then it is bottom. 5) When paving the side slope, the direction of paving film should substantially parallel to the maximum gradient line.
