Composite geomembranes are widely used in seepage prevention projects for channels. In recent years, the extensive application and effectiveness of geosynthetic materials in civil engineering, particularly in flood control and emergency rescue projects, have garnered great attention from engineering technicians. In terms of the application technology of geosynthetic materials, the state has proposed normative technical requirements from aspects such as seepage prevention, anti-filtering, drainage, reinforcement, and protection, significantly accelerating the promotion and application of new materials. This material is widely used in seepage prevention projects for irrigation channels, and in conjunction with construction practices, this article briefly discusses the application technology of composite geomembranes.

Composite geomembrane is produced by passing the geomembrane through an oven's far-infrared heating on one or both sides, then pressing the geotextile and geomembrane together with guide rollers to form a composite geomembrane. With advancements in production technology, a casting method has also been developed for making composite geomembranes. The configurations include one geotextile and one membrane, two geotextiles and one membrane, and two membranes and one geotextile, among others.

Geotextile serves as a protective layer for geomembrane, safeguarding the impermeable layer from damage. To reduce UV radiation and enhance aging resistance, it is best to lay it using the burial method.

During construction, first level the base surface with sand or clay of smaller diameter. Then, lay the geotextile membrane, ensuring it's not too tight. The ends buried in the soil should be wavy. Finally, cover the laid geotextile membrane with a fine sand or clay transition layer of approximately 250px. Construct a protective layer using 20-750px blocks (or concrete precast blocks). During construction, strive to avoid placing stones directly on the geotextile membrane; it's best to perform the protective layer installation as you lay the membrane. Connect the composite geotextile membrane to surrounding structures using expansion bolts and steel strips for anchoring. The connection points should be coated with emulsified asphalt (2mm thick) to prevent leakage.

Construction Matters

(1) Use should be embedded: The coverage thickness should not be less than 750px.

(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 compact and avoid uneven settling and cracking. Remove grass and tree roots within the anti-seepage area. Lay a protective layer of fine sand or clay in contact with the membrane.

(4) When laying the geotextile membrane, do not stretch it too tightly. It's better for the ends buried in the soil to form a wavy pattern, especially when anchored with rigid materials, some allowance for expansion and contraction should be left.

(5) During construction, it is advisable to avoid having stones or heavy objects directly fall on the geotextile membrane. It is best to construct, lay the membrane, and cover with a protective layer simultaneously.