Components, systems and materials › Slope protection and rockfall › Geotextile
Geotextile
What it is
A geotextile is a permeable fabric made of polymer fibres, used in contact with soil to separate, filter, drain, reinforce or protect.
Where it is used
Under road and rail layers, behind retaining walls and gabions, around drains, under rip-rap, and as cushion layers for landfill liners.
How it works
In separation, it stops a weak subgrade mixing with the aggregate above. In filtration, it lets water through while holding soil particles. In drainage, thick fabrics carry water within their plane. In reinforcement, woven fabrics carry tension. In protection, heavy fabrics cushion membranes against puncture.
Types
- Woven geotextiles
- nonwoven needle-punched geotextiles
- nonwoven heat-bonded geotextiles
- knitted geotextiles
Materials
Mainly polypropylene and polyester fibres.
Selection follows function: opening size and permeability for filtration, tensile strength for reinforcement, puncture resistance for survival during construction. IRC:SP:59 gives guidance for road works.
Installation and QA steps
- Prepare the surface
- Unroll fabric with overlaps or seams as specified
- Avoid wrinkles and tears
- Place fill without driving directly on the fabric
- Cover quickly to avoid sunlight exposure
- Clogged filter from wrong opening size
- Tears by construction plant
- UV degradation from long exposure
- Too little overlap on soft ground
Codes cited
- IRC:SP:59 (India): Guidelines for use of geosynthetics in road pavements and associated works.
- BS 8006-1 (UK): Code of practice for strengthened/reinforced soils and other fills.
Cited by number only. We do not reproduce code text, tables or figures.
Related
Generic description for education. We do not name, endorse or compare manufacturers or products.
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