Precautions for construction of composite geomembrane

Precautions for construction of composite geomembrane

Composite geomembrane is formed by pasting geotextile on one or both sides of the membrane. Its forms include one cloth and one film, two cloth and one film, two films and one cloth, etc.

As the protective layer of the geomembrane, the geotextile can protect the impermeable layer from damage. In order to reduce the ultraviolet radiation and increase the anti-aging performance, the embedding method is adopted.

During construction, the foundation surface shall be leveled with sand or clay with smaller material diameter, and then the geomembrane shall be laid. The geomembrane shall not be too tight, and the parts buried in the soil at both ends are corrugated. A layer of about 10cm transition layer shall be paved on the geomembrane with fine sand or clay. Build 20-30cm block stones (or concrete precast blocks) as the erosion protection layer. During the construction, try to avoid the stone directly hitting the geomembrane, which is the construction of protective layer while paving the membrane. The connection between the composite geomembrane and the surrounding structures shall be anchored with expansion bolts and steel plate battens, and the connection part shall be coated with emulsified asphalt (2mm thick) for bonding to prevent leakage.

The joint treatment of composite geomembrane is a key process, which directly affects the anti-seepage effect. The general joint methods are: ① Lap: the lap width should be greater than 15cm; ② Hot welding: It is suitable for slightly thick geomembrane substrate, and the overlap width of the weld is not less than 5CM

According to many years of practice, the thickness of the geomembrane is not less than 0.25mm. If the geomembrane is too thin, air holes may occur, and it is easy to be damaged in construction and reduce the anti-seepage effect. During the construction of geomembrane, special attention shall be paid to ensure that the laying is not too tight, no wrinkles are allowed, and the splicing is firm. The construction shall be carried out in strict accordance with the technical specifications, and the quality of preparation, laying, splicing, inspection and backfilling shall be ensured.