Role of Geobags in Environmental Engineering

The role of Geosynthetics in civil and environmental engineering is not new: they have been in use for more than three decades, and their benefits are well established. They last long, cost relatively little and can be used in many ways. One of the most versatile is the geobag, used in erosion control, drainage and filtration.

Geobags are bags made of woven or non-woven geotextiles. Because they are normally filled with sand, they are also called Geotextile Sand Containers (GSC). Their main use is coastline and riverbank protection, where they form a stabilizing, protective barrier.

Made of polyester, polyethylene or polypropylene, geobags are an alternative to traditional rock and concrete marine protection. They are easy to install and maintain, they can be removed if needed, and they have less impact on the environment, aquatic life and vegetation than hard structures. See how Ocean PET geobags were used on the Bambolim Dam project in Goa.

A geobag’s durability depends on its mechanical properties: wide-width tensile strength, elongation, seam strength, abrasion resistance, tear strength, puncture resistance and UV stability.

Fabrication details (number of stitch rows, thread type, the geotextile itself) and physical properties (thickness, mass per unit area, bag dimensions and fill mass) are set by the site and project specification.

Geotextile sand containers usually come in small, medium and large sizes. Small GSCs are used for temporary structures, medium ones for milder conditions and emergency works, and large ones for more permanent structures. The larger and heavier the bag, the more stable it is under waves and currents.

Where are Geobags used?

Geobags are used in many settings. In erosion control, they stop sand being carried off by tides and wave currents. As shoreline protection, they resist wave attack and absorb some of the wave energy. Vegetation can grow on and around them, which hard structures do not allow.

They protect coastal and inland waterways and resist abrasion and UV damage. As soft armour, they also give marine life a stable base to grow on. GSCs are used in both permanent and temporary installations.

Temporary structures: groynes, sea walls, riverbank protection.
Permanent structures: sea walls, revetments, slope buttressing, groynes, breakwaters, dykes, reefs, scour protection, dunes and permanent riverbank protection.

Advantages:

• Flexibility: usable in groynes, reefs, dunes, dams and more.
• Filling: filled on site with gravel or sand, so no heavy fill has to be transported.
• Environment: less disruptive than rock or concrete, and removable.
• Weights and Measures: Available in varied sizes and shapes, specific to design requirements.
• Cost-Effective: usually cheaper than conventional materials to make and install.
• Technology and durability: double-stitched seams and quality control during fabrication.
• Logistics: empty bags are light and compact, so they can be moved quickly in an emergency and filled where they are needed.

Ocean Geosynthetics manufactures and supplies geobags in woven and non-woven geotextile, sized to the project.

Call us to discuss geobags for your project.