Composite geomembrane is a geotextile anti-seepage material composed of plastic film as the anti-seepage substrate and non-woven fabric. Its anti-seepage performance mainly depends on the anti-seepage performance of the plastic film. The plastic films used for anti-seepage applications both domestically and internationally mainly include polyvinyl chloride (PVC), polyethylene (PE), and ethylene/vinyl acetate copolymer (EVA). They are a type of polymer chemical flexible material with low specific gravity, strong extensibility, high adaptability to deformation, corrosion resistance, low temperature resistance, and good frost resistance.
The service life of composite geomembranes is mainly determined by whether the plastic film loses its anti-seepage and water-resistant properties. According to Soviet national standards, polyethylene films with a thickness of 0.2m and stabilizers used in water engineering can work for 40-50 years under clear water conditions and 30-40 years under sewage conditions. Therefore, the service life of composite geomembrane is sufficient to meet the anti-seepage requirements of the dam.
Scope of geomembrane
The reservoir dam was originally a core wall dam, but due to the collapse of the dam, the upper part of the core wall was disconnected. To solve the problem of upper anti-seepage, an anti-seepage inclined wall was originally added. According to the safety assessment and analysis of the Zhoutou Reservoir dam, in order to solve the weak leakage surface and dam foundation leakage caused by multiple landslides of the dam, vertical anti-seepage measures such as bedrock curtain grouting, contact surface grouting, flushing and grabbing sleeve well backfilling curtain, and high-pressure spray anti-seepage plate wall were adopted. The upper inclined wall is covered with composite geomembrane for anti-seepage, and is connected to the vertical anti-seepage wall at the bottom, reaching an elevation of 358.0m (0.97m above the check flood level)
major function
1. Integrating anti-seepage and drainage functions, while also possessing functions such as isolation and reinforcement.
2. High composite strength, high peel strength, and high puncture resistance.
3. Strong drainage capacity, high friction coefficient, and low linear expansion coefficient.
Post time: Nov-15-2024