How Geotextile bags makes Civil Engineering Easier?

A geotextile bag, also known as a geobag, is a large synthetic fabric bag used in civil engineering and environmental work. Geotextile bags are filled with sand, soil or other granular material and stacked to form retaining walls, breakwaters, revetments and erosion control barriers. They are also used for shoreline protection, land reclamation and sediment containment in water bodies. The fabric lets water pass through while holding the fill in, so the bag stays heavy and stable without building up water pressure.

Geotextile bags use the same permeable fabric functions as flat geotextiles (filtration, separation, protection and drainage), with the fabric stabilised against UV so the bags survive exposure on banks and shorelines. They go by several names:

• Geo Bag
• Non-Woven/Woven Geo Bag
• Geotextile Sand Container
• Sand Bags

What is the use of geotextile bags in Civil Engineering?

The main civil engineering uses of geo bags:

1. Erosion control: Geo bags stabilise slopes and riverbanks by armouring the face, slowing water flow and retaining soil particles. For an example, see the Chhapra, Bihar riverbank project.
2. Shoreline protection: Geo bags can protect shorelines from erosion caused by waves and currents. They can be stacked to form breakwaters and groynes or placed along the shore as revetments and beach nourishment cores.
3. Retaining walls: Stacked geo bags make low retaining walls that are cheaper and quicker to build than concrete walls, and they tolerate settlement.
4. Land reclamation: Bags filled with dredged sand form the perimeter bunds that hold reclaimed fill in place.
5. Flood control: Geo bags are used to raise and repair embankments, close breaches and build temporary or permanent flood walls.

How do Geo bags make Civil Engineering Easier?

Geo bags make work easier in four ways:

1. Ease of installation: Geo bags can be easily transported to a construction site and filled with local soil or other materials. Small bags can be filled and placed by hand without heavy equipment or skilled labour, which saves time and cost on remote banks where stone and machinery are hard to bring in.
2. Flexibility: Filled bags deform to fit the bank or bed under them and to each other, so a geobag structure settles with scour instead of cracking. They can be built in almost any shape.
3. Environmental benefits: The fill is local sand, often from the same river, so there is no quarrying or long-haul transport of stone. The permeable fabric drains the bank and lets vegetation establish over bags that are covered with soil.
4. Cost-effectiveness: Geo bags are often cheaper than concrete, stone or steel, especially where stone has to be transported a long way. Temporary bag structures can be cut open and the fill reused.

What are geo bags specification?

Geo bags specifications vary with the application and between geo bags manufacturers in India. These are the usual parameters:

1. Material: Geo bags are usually made of high-strength non-woven geotextile fabrics in polypropylene or polyester; woven bags are also used. The fabric should be UV stabilised and resistant to chemicals and biological attack. Fabric mass (GSM), seam strength and opening size are specified alongside the bag dimensions.
2. Size: Geo bags range from about 0.5 to 5 metres in length and width. A filled bag is much flatter than it is long or wide. The size depends on the application: bigger, heavier bags resist stronger currents and waves, while smaller bags are easier to fill and place by hand.
3. Capacity: Geo bags hold sand, soil or gravel. Capacity depends on bag size and fill level; bags are usually filled to around 80% of capacity so they stay soft enough to bed down against each other.
4. Strength: Fabric strength is specified as tensile strength, tear resistance and puncture resistance, plus seam strength for the bag. The bag has to survive filling, lifting and dropping into place, not only the service loads.
5. Permeability: The fabric must let water through while retaining the fill. This is set by its permittivity (ASTM D4491) and apparent opening size (ASTM D4751), which is matched to the grading of the fill sand.
6. Ultraviolet (UV) resistance: The fabric of the geo bag should have good resistance to ultraviolet (UV) radiation, which can cause degradation and reduce the bag’s lifespan.

Geo bags manufacturers in India

Ocean Global makes geotextile bags in a range of sizes, fabric weights and materials (non-woven polypropylene, non-woven polyester and woven) for river, coastal and flood work. Bags can be made to the size and fabric grade a design calls for.

Ocean Global has more than 21 years of experience as one of the geo bags manufacturers in India. Recent supplies include 27,000 non-woven PP 300 GSM geobags for an irrigation and riverbank project in Howrah, West Bengal.

Frequently Asked Questions (FAQs)