lay

Before laying the anti-seepage geomembrane, the corresponding qualified acceptance certificate of the civil engineering should be obtained.

Before cutting the anti-seepage geomembrane, its relevant dimensions should be accurately measured and then cut according to the actual size. Generally, it is not advisable

to cut according to the dimensions shown in the diagram, and each piece should be numbered and recorded in detail on a dedicated table.

3. When laying geomembrane, efforts should be made to minimize the number of welds, and raw materials should be saved as much as possible while ensuring quality.

It is also easy to ensure quality.

4. The overlap width between membranes is generally not less than 10cm, and the welding seam is usually arranged parallel to the maximum slope, that is, along the slope direction.

5. Usually, in corners and deformed areas, the joint length should be minimized as much as possible. Unless otherwise specified, welding seams should be avoided as much

 as possible within a range of 1.5 meters from the top slope or stress concentration area on slopes with a gradient greater than 1:6.

During the laying of geomembranes, artificial wrinkles should be avoided. When the temperature is low, they should be tightened and leveled as much as possible.

7. After the installation of the geomembrane is completed, efforts should be made to minimize walking or moving tools on the surface of the membrane. Any objects that 

can cause harm to the HDPE membrane should not be placed on or carried on the membrane to avoid accidental damage to the membrane.

Do not drag or forcefully pull the anti-seepage geomembrane during transportation to avoid sharp objects from puncturing it.

1. It should extend from the bottom to the high position, without pulling too tightly, leaving a margin of 1.50% for local sinking and stretching. Considering the actual situation

 of this project, the slope will be laid in a top-down sequence;

2. The longitudinal joints of adjacent frames should not be on the same horizontal line and should be staggered by more than 1m from each other;

3. The longitudinal head should be at least 1.50m away from the dam foot and curved foot, and should be placed on a flat surface;

4. First, the bottom of the slope;

5. When laying the slope, the direction of the film should be basically parallel to the maximum slope line.

welding

1. The welding process of the hot wedge welding machine is divided into: adjusting the pressure, setting the temperature, setting the speed, inspecting the overlap of the weld

 seam, installing the film into the machine, starting the motor, and applying pressure for welding.

2. There should be no oil stains or dust at the joints, and the overlapping section of HDPE geomembrane should not contain mud or other debris. If there are any debris, they 

must be cleaned before welding.

3. At the beginning of each welding day, a 0.9mm × 0.3mm sample must be tested and welded on site, with a lap width of not less than 10cm, and a tensile machine must be 

used for peeling and shearing tests on site. After the sample is qualified, the speed, pressure, and temperature adjusted at that time can be used for formal welding. The date,

time, and ambient temperature should be indicated on the sample. During the welding process of the hot wedge welding machine, it is necessary to pay attention to the

operation of the welding machine at all times and adjust the speed and temperature according to the actual situation on site.

4. The weld seam should be neat, beautiful, and free from any sliding or jumping phenomena.

When encountering insufficient length of geomembrane, longitudinal splicing is required. The transverse welds should be welded first, and then the longitudinal welds should

be welded. If the distance between the transverse welds is greater than 50cm, they should form a T shape and not cross each other.

6. Adjacent geomembrane welds should be staggered and overlapped as much as possible. The nodes formed between the membrane blocks should be T-shaped, and cross

shaped joints should be minimized as much as possible. Extrusion welding machines should be used to strengthen the intersection points of the longitudinal mold and weld seams.