In modern engineering construction, a seemingly ordinary yet crucial material—geomembranes—is becoming an indispensable anti-seepage barrier in various fields such as water conservancy, environmental protection, and transportation, thanks to their exceptional impermeability and flexible application characteristics. From stabilizing railway roadbeds on salt lakes to preventing seepage in reservoir dams, from isolating aquaculture ponds to environmental protection in landfill sites, the application of geomembranes continues to expand. Equally noteworthy is the journey of domestic technological development and industry standards breakthroughs behind them.

1. What Are Geomembranes?

Geomembranes, commonly known as anti-seepage membranes, are impermeable materials made from synthetic polymer materials such as high-density polyethylene (HDPE) and polypropylene (PP). Using plastic film as the base impermeable material combined with non-woven fabric, their core function is to create a waterproof barrier that effectively prevents liquids from penetrating soil or other substrates. This material not only boasts characteristics such as corrosion resistance, aging resistance, and high mechanical strength but also exhibits excellent flexibility and adaptability to deformation, making it suitable for various complex environments.

The primary component of geomembranes is polyethylene virgin resin, with approximately 97.5% being high-density polyethylene (HDPE), supplemented by about 2.5% of carbon black, anti-aging agents, antioxidants, UV absorbers, and stabilizers. These components collectively ensure the stability and long service life of geomembranes under extreme conditions.

2. Exceptional Performance: The All-Rounder in Anti-Seepage Engineering

Geomembranes demonstrate multiple advantages in anti-seepage engineering:

1. ​​Excellent Impermeability​​: With an extremely low permeability coefficient, typically in the range of 10−17to 10−14m/s, geomembranes significantly reduce the risk of liquid leakage.
2. ​​Strong Chemical Stability​​: They resist corrosion from over 80 types of strong acids, alkalis, and organic solvents, making them widely used in scenarios such as sewage treatment, chemical reaction tanks, and landfill sites.
3. ​​Aging and UV Resistance​​: Geomembranes possess excellent anti-decomposition capabilities, can be used exposed, and have a service life of 50–70 years.
4. ​​Convenient and Economical Construction​​: Compared to traditional concrete lining or soil sealing techniques, geomembrane installation is faster, effectively saving time and labor resources. Although initial investment may be slightly higher, the rapid construction speed and low maintenance costs make them highly economical overall.
5. ​​Environmentally Friendly and Non-Toxic​​: Made from non-toxic, environmentally friendly materials, geomembranes function through physical changes without producing harmful substances, making them ideal for environmental protection, aquaculture, and drinking water ponds.

3. Wide Applications: From Major Projects to Civilian Fields

Geomembranes are used in a wide range of applications, covering almost all engineering fields that require seepage prevention and isolation:

• ​​Water Conservancy Projects​​: Such as seepage prevention in reservoirs, channels, artificial lakes, and dams.
• ​​Environmental Sanitation​​: Including landfill seepage prevention and leachate collection isolation filtration systems, sewage treatment pond seepage prevention, etc., to prevent harmful substances from infiltrating groundwater sources.
• ​​Transportation​​: Used for subgrade reinforcement, seepage prevention, and drainage in railways and highways.
• ​​Petrochemical Industry​​: Seepage prevention and anti-corrosion lining for chemical sewage pools, oil refinery sewage pools, and oil tank foundations.
• ​​Mining​​: Seepage prevention in washing pools, heap leaching pools, and tailing dams.
• ​​Agriculture, Forestry, Animal Husbandry, and Fisheries​​: Seepage prevention for reservoirs, drinking water pools, and storage pools; intensive aquaculture ponds and fish pond seepage prevention. For example, Maoming Petrochemical's special geomembrane material has achieved good anti-seepage effects in aquaculture applications.
• ​​Municipal Construction​​: Such as tunnel drainage, drainage and pressure reduction in underground construction projects, and rooftop garden seepage prevention.

4. Technical Core: Meticulous Material and Process Optimization

The performance of geomembranes largely depends on their materials and production processes. ​​High-Density Polyethylene (HDPE)​​ geomembranes are the preferred choice in many harsh environments due to their excellent mechanical properties and resistance to environmental stress cracking.

​​Welding technology​​ is a critical link in geomembrane construction, directly affecting the integrity of the anti-seepage system. The two main methods currently used are ​​dual-track hot wedge welding​​ and ​​single-track extrusion welding​​. Before welding, the membrane surface must be cleaned to ensure no oil stains, dust impurities, and trial welding and tensile tests should be conducted on-site to ensure welding quality. The weld overlap is typically required to be no less than 10 cm and should avoid stress concentration areas.

5. Future Prospects: Intelligent and Green Development

With technological advancements, the future development of geomembranes will focus more on enhancing environmental performance and integrating digital monitoring technologies. Developing materials with stronger UV resistance will improve their durability. Meanwhile, the integration of real-time monitoring technology will enable the status of geomembranes to be perceived in real time, providing stronger and smarter support for the anti-seepage needs of infrastructure.

Conclusion

As a critical anti-seepage barrier, geomembranes will continue to play an indispensable role in national economic construction and ecological protection. The continuous improvement of industry standards and technological innovation also indicates that China's geosynthetic materials sector will embrace broader development prospects, building an "underground Great Wall" for more major projects.