Geotextiles are permeable fabrics which, when used in association with

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

, have the ability to separate, filter, reinforce, protect, or drain. Typically made from

polypropylene Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer propylene. Polypropylene belongs to the group of polyolefins an ...

or polyester, geotextile fabrics come in two basic forms: woven (resembling mail bag sacking) and nonwoven (resembling felt). Geotextile composites have been introduced and products such as geogrids and meshes have been developed. Geotextiles are durable and are able to soften a fall. Overall, these materials are referred to as geosynthetics and each configuration— geonets, geosynthetic clay liners, geogrids, geotextile tubes, and others—can yield benefits in geotechnical and

environmental engineering Environmental engineering is a professional engineering discipline that encompasses broad scientific topics like chemistry, biology, ecology, geology, hydraulics, hydrology, microbiology, and mathematics to create solutions that will protect and ...

design.

History

Geotextiles were originally intended to be a substitute for granular

filters. The original, and still sometimes used, term for geotextiles is ''filter fabrics''. Work originally began in the 1950s with R.J. Barrett using geotextiles behind precast concrete seawalls, under precast concrete erosion control blocks, beneath large stone riprap, and in other erosion control situations. He used different styles of woven monofilament fabrics, all characterized by a relatively high percentage open area (varying from 6 to 30%). He discussed the need for both adequate permeability and soil retention, along with adequate fabric strength and proper elongation and set the tone for geotextile use in filtration situations.

Applications

Geotextiles and related products have many applications and currently support many

civil engineering Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewa ...

applications including

road A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of ...

airfield An aerodrome (Commonwealth English) or airdrome (American English) is a location from which aircraft flight operations take place, regardless of whether they involve air cargo, passengers, or neither, and regardless of whether it is for publ ...

railroad Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...

s, embankments, retaining structures,

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including control ...

canal Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface fl ...

s, dams,

bank A bank is a financial institution that accepts deposits from the public and creates a demand deposit while simultaneously making loans. Lending activities can be directly performed by the bank or indirectly through capital markets. Becau ...

protection, coastal engineering and

construction Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and ...

site silt fences or geotube. Usually geotextiles are placed at the tension surface to strengthen the soil. Geotextiles are also used for sand

dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, fl ...

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 Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is di ...

from proceeding beyond the SFC. Using a sloped unit rather than a single tube eliminates damaging scour. 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 Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...

from

rain Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water ...

, and

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

roots. In building demolition, geotextile fabrics in combination with steel wire fencing can contain explosive debris. Coir (coconut fiber) geotextiles are popular 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 In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Lati ...

, enriching the soil.

Global warming

Glacier retreat

Geotextiles with reflective properties are used in protecting the melting

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such a ...

s. In north

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

, they use Geotextiles to cover the glaciers for protecting from the Sun.

Design methods

While many possible design methods or combinations of methods are available to the geotextile designer, the ultimate decision for a particular application usually takes one of three directions: design by cost and availability, design by specification, or design by function. Extensive literature on design methods for geotextiles has been published in the peer reviewed journal ''

Geotextiles and Geomembranes ''Geotextiles and Geomembranes'' is a bimonthly peer-reviewed scientific journal. It is the official journal of the International Geosynthetics Society and published on their behalf by Elsevier. The journal covers all topics relating to geosyntheti ...

''.

Requirements

Geotextiles are needed for specific requirements, just as anything else in the world. Some of these requirements consist of polymers composed of a minimum of 85% by weight poly-propylene, polyesters, polyamides, polyolefins, and polyethylene. https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs144p2_016396.pdf

History

Applications

Global warming

Glacier retreat

Design methods

Requirements

See also

References

Further reading