Abstract: A geotextile is typically defined as any permeable textile material used to increase soil stability, provide erosion control or aid in drainage and in civil construction. More simply put, if it is made of fabric and buried in the ground it is probably a geotextile!
Geotextiles have been in use for thousands of years dating back to the Egyptian Pharaohs. These early geotextile applications were basically natural fibers or vegetation mixed directly with soil. Modern geotextiles are usually made from a synthetic polymer such as polypropylene, polyester, polyethylene and polyamides. Geotextiles can be woven, knitted or non-woven. Varying polymers and manufacturing processes result in an array of geotextiles suitable for a variety of civil construction applications.
Geotextile composites have been introduced and products such as geogrids and meshes have been developed. Overall, these materials are referred to as geo synthetics and each configuration geonets, geogrids and others can yield benefits in geotechnical and environmental engineering design.
Non-woven geotextiles: Resemble felt and provide planar water flow. They are commonly known as filter fabrics, although woven monofilament geotextiles can also be referred to as filter fabrics. Typical applications for non-woven geotextiles include aggregate drains, asphalt pavement overlays and erosion control.
woven geotextile: A woven geotextile is a planar textile structure produced by interlacing two or more sets of strands at right angles. There are two types of strands: slit films, which are flat; and monofilaments, which are round. Woven slit-film geotextiles are generally preferred for applications where high strength properties are needed and filtration requirements are less critical.
These fabrics reduce localized shear failure in weak subsoil conditions and aid construction over soft subsoils. Woven monofilament geotextiles are preferred for applications where both strength and filtration are a concern, such as shoreline rip rap applications.
Geotextile-related materials such as fabrics formed into mats, webs, nets, grids, or formed plastic sheets are not the same as geotextiles. These would fall under the more general category of geosynthetics.
Applications: Geotextiles and related products have many applications and currently support many civil engineering applications including roads, airfields, railroads, embankments, retaining structures, reservoirs, canals, dams, bank protection, coastal engineering and construction site silt fences. Usually geotextiles are placed at the tension surface to strengthen the soil. Geotextiles are also used for sand dune armoring to protect upland coastal property from storm surge, wave action and flooding. A large sand-filled container (SFC) within the dune system prevents storm erosion from proceeding beyond the SFC. Using a sloped unit brather than a single tube eliminates damaging court.
EROSION CONTROL: Manuals comment on the effectiveness of sloped, stepped shapes in mitigating shoreline erosion damage from storms. Geotextile sand-filled units provide a “soft” armoring solution for upland property protection. Geotextiles are used as matting to stabilize flow in stream channels and swales.
Geotextiles can improve soil strength at a lower cost than conventional soil nailing. In addition, geotextiles allow planting on steep slopes, further securing the slope.
Geotextiles have been used to protect the fossil hominid footprints of Laetoli in Tanzania from erosion, rain, and tree roots.
In building demolition, geotextile fabrics in combination with steel wire fencing can contain explosive debris.
Coir (coconut fiber) geotextiles are a popular solution for erosion control, slope stabilization and bioengineering, due to the fabric’s substantial mechanical strength. Coir geotextiles last approximately 3 to 5 years depending on the fabric weight. The product degrades into humus, enriching the soil.
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