Filter Cloths

 

Filter cloths is a relatively new topic in foundation construction.  Filter cloths, including geotextiles, are permeable fabrics which, when used in association with soil, have the ability to separate, filter, reinforce, protect or drain.  Applications in civil engineering include roads, airfields, embankments, retaining structures, bank protection & stabilization, canals, dams, coastal engineering, etc.  Included below are sites to reference for information regarding the technology of filter cloths.
 

              ;  www.elsevier.nl/inca /publications/store/4/0/5/8/9/7/

              ;   www.elsevier, nl/homepage/search.htt?sarea=sad&sarea=saf

              ;   www.geosource.com/

              ;   www.geomembrane.com/

              ;   www.tenax.com/

              ;   www.geofoam.org/

              ;   www.ice.org.uk/ice/institut/assoc. html

GEOSYNTHETIC DEFINITIONS

Geotextiles: Any permeable textile material used with soil, rock, or any other geotechnical engineering related material, as an integral part of a man-made project, structure or system.

Geogrid: A deformed or non-deformed grid-like polymeric material formed by intersecting ribs joined at the junctions and used for reinforcement with soil, rock or any other geotechnical engineering related material as an integral part of a man-made project, structure or system.

Geomembrane: Very low permeability synthetic membrane liners or barriers used with any geotechnical engineering related material so as to control fluid migration in a man-made project, structure or system.

Geocomposite: A product fabricated from any combination of geosynthetics.

EXAMPLES OF FILTER CLOTH APPLICATIONS

 

AN EROSION CONTROL APPLICATION

The role of the total system is to prevent erosion of the soil materials along the channel. The geotextile performs the specific function of filtration, allowing water in the soil to pass through the fabric while retaining the soil particles.

REINFORCEMENT APPLICATION

In the reinforcement function, the geosynthetic is subjected to a sustained tensile force or load. Soil and rock materials are noted for their ability to withstand compressive forces and their relative low capacity for sustained tensile forces. In the figure shown, the geosynthetic reinforces a levee constructed over soft soils. The geosynthetic layers are place across potential rotational failure planes to carry the tensile forces which cannot be carried by an unreinforced soil mass.

 

TRANSMISSION APPLICATION

A geotextile alone may be used in the transmission function. As shown in the figure, a geotextile/drainage core composite can provide drainage adjacent to the face of a retaining wall. Fluid enters the composite through the geotextile and is carried in the channels of the core to a desired location in the project.

 

 

 

Prepared by Kimberley Oldham, Dec. 1997