Geomembrane: What is Geosynthetic and its Uses in Environmental Protection and Infrastructure Projects

 

Geomembrane 

Introduction to Geomembrane

Geosynthetics are synthetic membrane liners or barriers used in construction for waterproofing, drainage, protection, and as containment vessels for liquids. These thin, flexible sheets are made from polymers like high-density polyethylene (HDPE), polyvinyl chloride (PVC), Ethylene Propylene Diene Monomer Rubber (EPDM), polypropylene (PP), and others. Geosynthetics are engineered to resist corrosion, ultraviolet radiation from sunlight, and chemical damage for extremely long periods, making them suitable for numerous infrastructure and environmental applications.

Uses in Environmental Protection

Geosynthetics play an important role in environmental protection through applications like landfill lining, mining containment, and wastewater treatment. In landfill lining systems, a geosynthetic layer is placed between the waste and ground surface to isolate landfill leachate and prevent contamination of groundwater. It acts as the primary barrier, with additional compacted soil and drainage layers for further pollution control. Geosynthetic clay liners made of bentonite or other swelling clays can be combined with geosynthetics for enhanced performance in semi-arid and arid areas.

In mining operations, tailings pond liners made of thick HDPE geosynthetics are used to surround tailings storage facilities. These store millions of tons of fine waste rock particles and process fluids. The impermeable liners prevent seepage of contaminated drainage into the surrounding surface and subsurface environments. Geosynthetics are also used to line leach pads and solution ponds in heap leach operations for recovering metals like gold and copper.

Wastewater lagoons and treatment ponds rely on Geomembrane to contain effluent on a semi-permanent basis. Municipal sewage and industrial treatment systems line storage cells, digesters, aeration basins, and clarifiers with flexible membrane liners. This eliminates contamination risks to nearby land and water resources from process leaks or accidental discharges. Geosynthetics enhance functionality of constructed wetlands used for polishing secondary effluent before discharge or reuse.

Infrastructure Applications

Construction and transportation infrastructure projects utilize geosynthetics for multiple purposes. Highway and railway embankments are stabilized and made impermeable through geoclay and geosynthetic composite lining systems. Underground utility vaults, tunnels, and transportation tunnels rely on membrane structures for groundwater cut-off and waterproofing during construction. HDPE geosynthetics are commonly used for waterproofing and damp-proofing foundations, basement walls, retaining walls, planter boxes, green roofs, and other below-grade structures.

Some specialized uses in infrastructure include HDPE geosynthetic pond liners for irrigation water storage, bentonite-amended geosynthetics for canal lining, and PVC liner applications in potable water reservoirs, tanks, and pipes. Geosynthetics find application as water barriers below bridge decks and elevated highways. They are used in tunnel boring machine (TBM) tunnel construction for segmental lining, groundwater control, and temporary tunnel bulkheads during sequential excavation and service installation works.

Manufacturing Process

Most geosynthetics are produced by extrusion of polymer resins. In this continuous process, resin pellets are fed into an extruder barrel where they are heated and forced through a die opening to form a continuous sheet. The molten sheet passes through nip rollers for gauging and is wound onto large rolls. Common widths range from 1.5 to 6 m. Cross-linked formulations enhance long-term chemical resistance and puncture/tear strength. The membrane sheets can be field seamed or factory seamed using extrusion welding, heat welding, or adhesive bonding techniques.

Quality Assurance and Installation

Proper installation is critical to performance of geosynthetics. Substrates are prepared with a smooth and compacted surface free of sharp objects, voids, or protrusions that could puncture or tear the liner. Anchor or toe trenches are excavated around the perimeter. The liner is then placed according to engineering design specifications and folded or cut to size using heat-sealing methods. Ballast materials like sandbags are placed to prevent wind uplift and to maintain contact between liner and underlying layer. Drainage geocomposites and leachate collection pipes are installed concurrently with the geosynthetic.

Geomembrane have provided breakthrough solutions for numerous environmental and civil engineering challenges by serving as impermeable, durable, and containment barriers. Their flexibility and welding compatibility allows conformance to complex liner geometries. Being inert and non-reactive chemically, geosynthetics are well-suited for applications exposed to hazardous leachates and industrial process fluids. With continuous advancements in polymer formulation and installation techniques, geosynthetics will remain indispensable lining components in water and pollution management infrastructure globally.

 

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Ravina Pandya, Content Writer, has a strong foothold in the market research industry. She specializes in writing well-researched articles from different industries, including food and beverages, information and technology, healthcare, chemical and materials, etc. (https://www.linkedin.com/in/ravina-pandya-1a3984191)