(1) Embedment required: coverage thickness should not be less than 30 cm

(2) The seepage prevention system should consist of: a base layer, a seepage prevention layer, a transition layer, and a protective layer.

(3) Ensure the soil is firm to avoid uneven settlement and cracks. Remove grass and tree roots within the seepage prevention area. Lay a protective layer of fine sand or clay in contact with the membrane.

(4) When laying geotextile membranes, do not stretch them too tightly. It's better for the ends buried in the soil to form a wavy pattern. Particularly when anchored with rigid materials, some degree of expansion and contraction should be allowed.

(5) During construction, it is essential to avoid placing stones or heavy objects directly on the geotextile membrane. Proceed with construction, lay the membrane, and then cover it with a protective layer simultaneously.

Composite geomembrane joints

The joint treatment of composite geomembranes is a crucial process, directly affecting the seepage prevention effect. Common joint methods include: 1. Lap joint: The lap width should be greater than 15cm; 2. Hot welding: Suitable for slightly thicker geomembrane base materials, with the welding seam lap width not less than 5cm. (Gluing is not recommended, as it is prone to delamination after long-term water immersion, resulting in poor seepage prevention effect.)

Seam Precautions

(1) The joint treatment of composite geomembranes is a critical construction procedure, directly affecting the service life of the project. Quality inspections indicate that the thermal welding method is ideal (adhesive bonding can also be used). The thermal welding method involves heating the surface of the PE geomembrane to melt it, then fusing it together under pressure.

(2) The geomembrane is laid in a specific direction, with both sides of the geomembrane leaving a certain layer of PE film and PET non-stick layer. During laying, the orientation of each geomembrane unit must be adjusted for easy welding between two units.

After laying the geomembrane, sandbags should be used to secure it against wind movement. The edges and seams must be free of any dirt, moisture, or dust.

Before welding, adjust the two edges of the PE single membrane at the joint so that they overlap a certain width, ensuring they are flat and free of wrinkles.

(5) Welding should be performed by technicians with some experience, using a welding machine for the process. Adjust the temperature and speed appropriately (adhesive bonding can also be used).

Based on years of practical experience, it has been proven that the thickness of geotextile membranes should not be less than 0.25mm, as being too thin may result in air pockets and is prone to damage during construction, thereby reducing the seepage prevention effect. During the construction of geotextile membranes, it is particularly important to ensure that the laying is not too tight, no wrinkles are formed, and the joints are firmly sealed. Construction must strictly adhere to technical specifications, and the five quality control points of preparation, laying, jointing, inspection, and backfilling must be strictly maintained.