Geotextile

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A selection of non-woven and woven geotextile samples Geotextile-GSI.JPG
A selection of non-woven and woven geotextile samples
Geotextile sandbags can be 20 m long, such as those used for the artificial reef at Narrow Neck, Queensland. Mega sand container.jpg
Geotextile sandbags can be 20 m long, such as those used for the artificial reef at Narrow Neck, Queensland.

Geotextiles are versatile permeable fabrics that, when used in conjunction with soil, can effectively perform multiple functions, including separation, filtration, reinforcement, protection, and drainage. Typically crafted from polypropylene or polyester, geotextile fabrics are available in two primary forms: woven, which resembles traditional mail bag sacking, and nonwoven, which resembles felt.

Contents

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 design.

History

Geotextiles were originally intended to be a substitute for granular soil filters. Geotextiles can also be referred to as filter fabrics. In the 1950s, R.J. Barrett began working using geotextiles behind precast concrete seawalls, under precast concrete erosion control blocks, beneath large stone riprap, and in other erosion control situations. [2] 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 tone setting for geotextile use in filtration situations.

Applications

A silt fence on a construction site. Silt fence EPA.jpg
A silt fence on a construction site.

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 or to form a geotextile tube. Geotextiles can also serve as components of other geosynthetics such as the reinforcing material in a bituminous geomembrane. 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 rather than a single tube eliminates damaging scour.

Geotextile sandbags protected the historic house Kliffende on Sylt island against storms, which eroded the cliffs left and right from the sandbag barrier. Kliffende, Island Sylt, 1999.jpg
Geotextile sandbags protected the historic house Kliffende on Sylt island against storms, which eroded the cliffs left and right from the sandbag barrier.

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. [3] [4]

Geotextiles can improve soil strength at a lower cost than conventional soil nailing. [5] 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. [6]

In building demolition, geotextile fabrics in combination with steel wire fencing can contain explosive debris. [7]

Coir (coconut fiber) geotextiles are popular for erosion control, slope stabilization and bioengineering, due to the fabric's substantial mechanical strength. [3] :App. I.E Coir geotextiles last approximately 3 to 5 years depending on the fabric weight. The product degrades into humus, enriching the soil. [8]

Geotextiles are also widely used in landfill applications, where they play a crucial role in ensuring the protection and long-term integrity of geomembrane liners. The product improve the leachate drainage and facilitate gas venting; features that are necessary for the environmental safety and stability of landfill systems. Geotextiles work by stabilizing slopes for newer landfills, preventing erosion and contamination between the waste, soil and other layers of the landfill site. [9]

Global warming

Glacial retreat

Geotextiles with reflective properties are often used in protecting the melting glaciers. In north Italy, they use Geotextiles to cover the glaciers for protection from the Sun. [10] The reflective properties of the geotextile reflect the sun away from the melting glacier in order to slow the process. However, this process has proven to be more expensive than effective.

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 .

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. [11]

See also

Related Research Articles

<span class="mw-page-title-main">Geotechnical engineering</span> Scientific study of earth materials in engineering problems

Geotechnical engineering, also known as geotechnics, is the branch of civil engineering concerned with the engineering behavior of earth materials. It uses the principles of soil mechanics and rock mechanics to solve its engineering problems. It also relies on knowledge of geology, hydrology, geophysics, and other related sciences.

<span class="mw-page-title-main">Leachate</span> A liquid that extracts soluble or suspended solids

A leachate is any liquid that, in the course of passing through matter, extracts soluble or suspended solids, or any other component of the material through which it has passed.

<span class="mw-page-title-main">Geosynthetics</span> Synthetic material used to stabilize terrain

Geosynthetics are synthetic products used to stabilize terrain. They are generally polymeric products used to solve civil engineering problems. This includes eight main product categories: geotextiles, geogrids, geonets, geomembranes, geosynthetic clay liners, geofoam, geocells and geocomposites. The polymeric nature of the products makes them suitable for use in the ground where high levels of durability are required. They can also be used in exposed applications. Geosynthetics are available in a wide range of forms and materials. These products have a wide range of applications and are currently used in many civil, geotechnical, transportation, geoenvironmental, hydraulic, and private development applications including roads, airfields, railroads, embankments, retaining structures, reservoirs, canals, dams, erosion control, sediment control, landfill liners, landfill covers, mining, aquaculture and agriculture.

<span class="mw-page-title-main">Pond liner</span>

A pond liner is an impermeable geomembrane used for retention of liquids, including the lining of reservoirs, retention basins, hazardous and nonhazardous surface impoundments, garden ponds and artificial streams in parks and gardens.

Landscape products are a group of building industry products used by garden designers and landscape architects and exhibited at trade fairs devoted to these industries. They include: walls, fences, paving, gardening tools, outdoor lighting, water features, fountains, garden furniture, garden ornaments, gazebos, garden buildings, and pond liners.

<span class="mw-page-title-main">Geocomposite</span> Composite material made up of multiple geosynthetic components.

Geocomposites are combinations of two or more geosynthetic materials for civil engineering applications that perform multiple geosynthetic functions; the five basic functions are: separation, reinforcement, filtration, drainage, and containment. Such composite materials may enhance technical properties of the soil or the geotechnical structure and minimize application costs.

A geomembrane is very low permeability synthetic membrane liner or barrier used with any geotechnical engineering related material so as to control fluid migration in a human-made project, structure, or system. Geomembranes are made from relatively thin continuous polymeric sheets, but they can also be made from the impregnation of geotextiles with asphalt, elastomer or polymer sprays, or as multilayered bitumen geocomposites. Continuous polymer sheet geomembranes are, by far, the most common.

<span class="mw-page-title-main">Geogrid</span> Synthetic material used to reinforce soils and similar materials

A geogrid is geosynthetic material used to reinforce soils and similar materials. Soils pull apart under tension. Compared to soil, geogrids are strong in tension. This fact allows them to transfer forces to a larger area of soil than would otherwise be the case.

<span class="mw-page-title-main">Geosynthetic clay liner</span> Type of hydraulic barrier

Geosynthetic clay liners (GCLs) are factory manufactured hydraulic barriers consisting of a layer of bentonite or other very low-permeability material supported by geotextiles and/or geomembranes, mechanically held together by needling, stitching, or chemical adhesives. Due to environmental laws, any seepage from landfills must be collected and properly disposed of, otherwise contamination of the surrounding ground water could cause major environmental and/or ecological problems. The lower the hydraulic conductivity the more effective the GCL will be at retaining seepage inside of the landfill. Bentonite composed predominantly (>70%) of montmorillonite or other expansive clays, are preferred and most commonly used in GCLs. A general GCL construction would consist of two layers of geosynthetics stitched together enclosing a layer of natural or processed sodium bentonite. Typically, woven and/or non-woven textile geosynthetics are used, however polyethylene or geomembrane layers or geogrid geotextiles materials have also been incorporated into the design or in place of a textile layer to increase strength. GCLs are produced by several large companies in North America, Europe, and Asia. The United States Environmental Protection Agency currently regulates landfill construction and design in the US through several legislations.

Regarding the civil engineering of shorelines, soft engineering is a shoreline management practice that uses sustainable ecological principles to restore shoreline stabilization and protect riparian habitats. Soft Shoreline Engineering (SSE) uses the strategic placement of organic materials such as vegetation, stones, sand, debris, and other structural materials to reduce erosion, enhance shoreline aesthetic, soften the land-water interface, and lower costs of ecological restoration.

<span class="mw-page-title-main">Technical textile</span> Textile product valued for its functional characteristics

"Technical textile" refers to a category of textiles specifically engineered and manufactured to serve functional purposes beyond traditional apparel and home furnishing applications. These textiles are designed with specific performance characteristics and properties, making them suitable for various industrial, medical, automotive, aerospace, and other technical applications. Unlike conventional textiles used for clothing or decoration, technical textiles are optimized to offer qualities such as strength, durability, flame resistance, chemical resistance, moisture management, and other specialized functionalities to meet the specific needs of diverse industries and sectors.

<span class="mw-page-title-main">Mechanically stabilized earth</span> Soil constructed with artificial reinforcing

Mechanically stabilized earth is soil constructed with artificial reinforcing. It can be used for retaining walls, bridge abutments, seawalls, and dikes. Although the basic principles of MSE have been used throughout history, MSE was developed in its current form in the 1960s. The reinforcing elements used can vary but include steel and geosynthetics.

Landslide mitigation refers to several human-made activities on slopes with the goal of lessening the effect of landslides. Landslides can be triggered by many, sometimes concomitant causes. In addition to shallow erosion or reduction of shear strength caused by seasonal rainfall, landslides may be triggered by anthropic activities, such as adding excessive weight above the slope, digging at mid-slope or at the foot of the slope. Often, individual phenomena join to generate instability over time, which often does not allow a reconstruction of the evolution of a particular landslide. Therefore, landslide hazard mitigation measures are not generally classified according to the phenomenon that might cause a landslide. Instead, they are classified by the sort of slope stabilization method used:

<span class="mw-page-title-main">Landfill liner</span> Barriers used to delay pollution from decomposing trash

A landfill liner, or composite liner, is intended to be a low permeable barrier, which is laid down under engineered landfill sites. Until it deteriorates, the liner retards migration of leachate, and its toxic constituents, into underlying aquifers or nearby rivers from causing potentially irreversible contamination of the local waterway and its sediments.

<span class="mw-page-title-main">Cellular confinement</span> Confinement system used in construction and geotechnical engineering

Cellular confinement systems (CCS)—also known as geocells—are widely used in construction for erosion control, soil stabilization on flat ground and steep slopes, channel protection, and structural reinforcement for load support and earth retention. Typical cellular confinement systems are geosynthetics made with ultrasonically welded high-density polyethylene (HDPE) strips or novel polymeric alloy (NPA)—and expanded on-site to form a honeycomb-like structure—and filled with sand, soil, rock, gravel or concrete.

A geonet is a geosynthetic material similar in structure to a geogrid, consisting of integrally connected parallel sets of ribs overlying similar sets at various angles for in-plane drainage of liquids or gases. Geonets are often laminated with geotextiles on one or both surfaces and are then referred to as drainage geocomposites. They are competitive with other drainage geocomposites having different core configurations.

Ronald Kerry Rowe, OC, BSc, BE, PhD, D.Eng, DSc (hc), FRS, FREng, NAE, FRSC, FCAE, Dist.M.ASCE, FEIC, FIE(Aust), FCSCE, PEng., CPEng. is a Canadian civil engineer of Australian birth, one of the pioneers of geosynthetics.

<span class="mw-page-title-main">Jean-Pierre Giroud</span>

Jean-Pierre Giroud is a French geotechnical engineer and a pioneer of geosynthetics since 1970. In 1977, he coined the words "geotextile" and "geomembrane", thus initiating the "geo-terminology". He is also a past president of the International Geosynthetics Society, member of the US National Academies, and Chevalier de la Légion d'Honneur.

<span class="mw-page-title-main">International Geosynthetics Society</span>

The International Geosynthetics Society (IGS) is an engineering professional society focused on the field of geosynthetics, which are polymeric materials used in geotechnical engineering. The IGS describes itself as "a learned society dedicated to the scientific and engineering development of geotextiles, geomembranes, related products, and associated technologies." It was founded in Paris in 1983 as the International Geotextile Society and is a member of the Federation of International Geo-Engineering Societies, along with the International Society of Soil Mechanics and Geotechnical Engineering (ISSMGE), International Society for Rock Mechanics and Rock Engineering (ISRM), and International Association for Engineering Geology and the Environment (IAEG).

<span class="mw-page-title-main">Bituminous geomembrane</span> Type of geomembrane

Bituminous geomembrane (BGM) is a type of geomembrane consisting of a reinforcing geotextile to provide mechanical strength and elastomeric bitumen to provide impermeability. Other components such as sand, a glass fleece, and/or a polyester film can be incorporated into the layers of a BGM. Bituminous geomembranes are differentiated from bituminous waterproofing materials used in buildings due in part to their wide roll width, which can exceed 5m, and their substantial thickness of up to 6.0mm.

References

  1. 1 2 Müller, W. W.; Saathoff, F. (2015). "Geosynthetics in geoenvironmental engineering". Science and Technology of Advanced Materials. 16 (3): 034605. Bibcode:2015STAdM..16c4605M. doi:10.1088/1468-6996/16/3/034605. PMC   5099829 . PMID   27877792.
  2. Barrett, R. J., "Use of Plastic Filters in Coastal Structures," Proceedings from the 16th International Conference Coastal Engineers, Tokyo, September 1966, pp. 1048–1067
  3. 1 2 Dane County Department of Land and Water Resources (2007). Dane County Erosion Control and Stormwater Management Manual (PDF) (Report). Madison, WI. Retrieved 2010-02-09.
  4. Massachusetts Department of Environmental Protection (2003). Massachusetts Erosion and Sediment Control Guidelines for Urban and Suburban Areas (PDF) (Report). Boston, MA. pp. 73–74.
  5. Morgan, Roy P.C.; Rickson, R.J. (2011). Slope Stabilization and Erosion Control: A Bioengineering Approach. London: Taylor & Francis. ISBN   9780419156307.
  6. Renfrew, Colin and Paul Bahn, Archaeology. 4th ed. New York: Thames 2004. ISBN   978-0-500-28441-4. [ page needed ]
  7. WGBH Boston (December 1996). "Interview with Stacey Loizeaux". NOVA Online . Public Broadcasting Service. Retrieved 2009-04-29. Other preparatory operations involve covering/wrapping the columns first with chain link fences and then with geotextile fabric, which is very puncture resistant and has a very high tensile strength. It allows the concrete to move, but it keeps the concrete from flying. The chain link catches the bigger material and the fabric catches the smaller material from flying up and out.
  8. Richards, Davi (2006-06-02). "Coir is sustainable alternative to peat moss in the garden". Garden Hints. Corvallis, OR: Oregon State University Extension Service. Retrieved 2013-03-06.
  9. Geotextiles in Landfills
  10. "Italian glaciers tell the tale of climate change; lost 1/3rd of its volume | Breaking News, Latest News, World, South Asia, India, Pakistan, Bangladesh News & Analysis". WION . Retrieved 2021-07-12.
  11. Material Specification 592—Geotextile (PDF) (Report). Vol. 642. January 2009. Archived from the original (PDF) on 2022-10-18.

Further reading