Download Geotextiles/Turf Reinforced Mats

GEOTEXTILES/TURF REINFORCED MATS
From Massachusetts Erosion and Sediment Control Guidelines for Urban and Suburban Areas
http://www.state.ma.us/dep/brp/stormwtr/files/esfull.pdf
Description:
Geotextiles are porous fabrics known in the construction industry as filter fabrics, road rugs, synthetic fabrics,
construction fabrics, or simply fabrics. Geotextiles are
manufactured by weaving or bonding fibers made from
synthetic materials such as polypropylene, polyester,
polyethylene, nylon, polyvinyl chloride, glass and various
mixtures of these. A subset of geotextiles includes Turf
Reinforced Mat (TRMs). TRMs combine vegetative growth
with synthetic materials to form a high-strength mat that
helps prevent soil erosion in drainage ways and on steep
slopes. Additionally, erosion control mats can be manufactured from coconut fibers (coir) with added strength by
including polypropylene fibers.
Close-up of a woven geotextile
fabric.
Purpose:
As a synthetic construction material, geotextiles are used for a variety of purposes in the
United States and other countries. The uses of geotextiles include separators, reinforcement,
filtration and drainage, and erosion control.
Where Practice Applies:
Geotextiles, when used alone, can be used as matting. TRMs are used to stabilize the flow in
channels and swales. TRMs may also be used on recently planted slopes to protect seedlings
until they become established and on tidal or stream banks where moving water is likely to
wash out new plantings.
Geotextiles are also used as separators. An example of such a use is geotextile as a separator
between riprap and soil. This ‘sandwiching’ prevents the soil from being eroded from
beneath the riprap and maintaining the riprap’s base. TRMs are classified as a soft engineering
approach as opposed to concrete and riprap. TRMs are composed of interwoven layers of
non-degradable geosynthetic materials such as polypropylene, nylon, and PVC netting, and
are usually stitched together to form a three-dimensional matrix. Soil can be placed in the
TRM which allows for vegetative root growth and soil stabilization or the mat can be placed
on the soil surface. TRM technology can be used in conjunction with temporary sediment
and erosion control measures to re-establish vegetation at construction sites.
TRM s are used to stabilize soil on steep slopes, to prevent scouring in stormwater detention
ponds, small open channels, drainage ditches, and runoff conveyance systems associated
with parking lots and other impervious surfaces.
Geotextiles/Turf Reinforced Mats pg.1
Massachusetts Nonpoint Source Pollution Management
Advantages:
• Fabrics are relatively inexpensive for certain applications as opposed to concrete
and riprap
• A wide variety of geotextiles to match specific needs is available.
• Natural fibers such as coconut can be woven into mats for erosion control.
• The result is a stabilized vegetated slope or swale.
Disadvantages/Problems:
• If the fabric is not property selected, designed, or installed, the effectiveness
may be reduced drastically.
• Many synthetic geotextiles are sensitive to light and must be protected prior
to installation.
Planning Considerations:
• There are numerous types of geotextiles available; therefore the selected fabric
should match its purpose. In the field, important concerns include regular
inspections to check for cracks, tears, or breaches in the fabric or mat.
Additional References:
U.S. Environmental Protection Agency, Storm Water Management For Construction Activities,
EPA-832-R- 92-005, Washington, DC, September, 1992.
U.S. Environmental Protection Agency, Stormwater Technology Fact Sheets – Turf Reinforced Mats.
EPA 832-F-99-002, September 1999.
Connecticut Council on Soil and Water Conservation. 2002 Connecticut Guidelines for Soil Erosion and
Sediment Control. DEP Bulletin 34.
Geotextiles/Turf Reinforced Mats pg.2
Massachusetts Nonpoint Source Pollution Management